Controlled release compositions and methods of using

ABSTRACT

Cyclodextrin compositions, including a hydrophobic carrier and a cyclodextrin complex, are formed and disposed on a variety of substrates using conditions that avoid substantial loss of the complexed compound from the cyclodextrin complex, even where the complexed compound is a gas a common ambient temperatures (e.g. 20° C.). Flexographic printing is particularly useful for disposing the cyclodextrin compositions on one or more substrates. Substrates treated with the cyclodextrin complexes are useful for subsequent release of the complexed compound.

BACKGROUND OF THE INVENTION

There is a substantial need in the art for improved plant maturation anddegradation prevention. In particular, pressure from worldwideurbanization, manufacturing, and population growth necessitatesdevelopment of new technologies to increase the efficiency and yield ofnatural resources expended on delivering food to the growing globalpopulation. In the United States, for example, it is estimated thatbetween 8% and 16% of profit loss of fresh produce is due to spoilageand shrinkage which is estimated at $8-$28 Billion system wide. Thisloss translates to significant wasted resources, for example pesticides,fertilizer, and herbicide use; land and water use; transportation,including oil and gas use; and resources associated with the storage ofproduce. Loss of these and other resources are due to inefficiencies inproduction and delivery that allows significant spoilage of fruits andvegetables before these critical products can reach the consumer. TheUnited Nations Asian and Pacific Centre for Agricultural Engineering andMachinery's Feasibility Study on the Application of Green Technology forSustainable Agriculture Development states:

-   -   “Technology is a link that connects sustainability with enhanced        productivity, where natural resource productivity is efficiently        maintained by carefully planning the conservation and        exploitation of resources such as soil, water, plants, and        animals.”        (Feasibility Study on the Application of Green Technology for        Sustainable Agriculture Development, United Nations Asian and        Centre for Agricultural Engineering and Machinery,        http://www.unapcaem.org/publication/GreenTech.pdf, at p. 20.)        Climate change is raising the stakes for agricultural technology        as the world population grows and the amount of arable land        shrinks. More mouths to feed, plus less arable land and changing        rainfall patterns, means growing demand for technology that lets        farmers do more with less. The European Commission recently        announced an initiative to optimize food packaging without        compromising safety in order to reduce food waste (Harrington,        R., “Packaging placed centre stage in European food waste        strategy,”        http://www.food.qualitynews.com/Public-Concerns/Packaging-placed-centre-stage-in-European-food-waste-strategy).        The initiative is in response to recent findings that up to 179        kg of food per person is wasted each year. The plan stresses the        need for innovation, such as “active packaging” or “intelligent        packaging” as one aspect of the solution. Technology that        addresses the issue of fruit and vegetable spoilage is therefore        of critical importance as a “green” technology that reduces        waste of food and its associated resources by increasing the        effective efficiency of arable land.

The shelf life of produce or produce materials, including whole plantsand parts thereof including fruits, vegetables, tubers, bulbs, cutflowers and other active respiring plants or plant materials, istypically determined, at least in part, by the amount of an ethylenegenerated by the respiring plant material. Ethylene is a known plantripening or maturation hormone. At any appreciable concentration ofethylene in and around living plant material, the maturation of theplant is initiated, maintained or accelerated, depending onconcentration. Ethylene-sensitive and -insensitive horticulturalcommodities (produce and ornamentals) are categorized as beingclimacteric or non-climacteric on the basis of the pattern of ethyleneproduction and responsiveness to externally added ethylene. Climactericcrops respond to ethylene by an early induction of an increase inrespiration and accelerated ripening in a concentration-dependentmanner. Non-climacteric crops ripen without ethylene and respirationbursts. However, some non-climacteric crops are sensitive to exogenousethylene, which can significantly reduce postharvest shelf life.Non-climacteric produce harbor several ethylene receptors which areactive. Therefore, exposure of non-climacteric produce to exogenousethylene can trigger physiological disorders shortening shelf life andquality. See, Burg et al., Plant Physiol. (1967) 42 144-152 andgenerally Fritz et al. U.S. Pat. No. 3,879,188. Many attempts have beenmade to either remove ethylene from the ambient package atmospheresurrounding the produce or to remove ethylene from the storageenvironment in an attempt to increase shelf life. Reduced ethyleneconcentration is understood to be achieved through a decrease in thestimulus of a specific ethylene receptor in plants. Many compounds otherthan ethylene interact with this receptor: some mimic the action ofethylene; others prevent ethylene from binding and thereby counteractits action.

Many compounds that act as an antagonist or inhibitor block the actionof ethylene by binding to the ethylene binding site. These compounds maybe used to counteract ethylene action. Unfortunately, they often diffusefrom the binding site over a period of several hours leading to a longerterm reduction in inhibition. See E. Sisler and C. Wood, Plant GrowthReg. 7, 181-191 (1988). Therefore, a problem with such compounds is thatexposure must be continuous if the effect is to last for more than a fewhours. Cyclopentadiene has been shown to be an effective blocking agentfor ethylene binding. See E. Sisler et al., Plant Growth Reg. 9, 157-164(1990). Methods of combating the ethylene response in plants withdiazocyclopentadiene and derivatives thereof are disclosed in U.S. Pat.No. 5,100,462 to Sisler et al. U.S. Pat. No. 5,518,988 to Sisler et al.describes the use of cyclopropenes having a C₁₋₄ alkyl group to blockthe action of ethylene.

Another suitable olefinic antagonist or inhibitor of receptor sites orethylene generation in produce is 1-methylcyclopropene (1-MCP).Derivatives and analogs thereof are also known to have antagonizing orinhibiting effects for the generation of ethylene from respiring plantor produce material or the reception thereof by receptors present on theliving plant material. Olefins including 1-MCP, 1-butene and others havebeen shown to have at least some measurable activity for extending shelflife via such a mechanism. A number of proposals have been made for themethod of producing and releasing 1-MCP to slow maturation andmaintaining the quality of plant materials. Currently 1-MCP is dispensedby the release of 1-MCP from a moisture activated powder or sachetcontaining complexed 1-MCP. In these technologies, 1-MCP is releasedfrom a point source which causes a concentration gradient within thestorage chamber thus resulting in a variation in maturation inhibitionwherein some produce has an extended life time where other produceexposed to a lesser concentration 1-MCP tends to have less inhibition ofethylene and has a reduced shelf life.

Further, 1-MCP is a gas in its natural state and is prone to violentautopolymerization (see e.g. EFSA Scientific Report (2005) 30, 1-46,Conclusion on the peer review of 1-methylcyclopropene, 2 May 2005). Forthis reason, 1-MCP is typically complexed with carrier materials such asα-cyclodextrin (see, e.g., Toivonen et al., U.S. Patent Publication No.2006/0154822). However, even when this is done, there are problems thatstill persist. The 1-MCP will rapidly release when exposed to waterand/or water vapor. (Neoh, T. L., et al., Carbohydrate Research 345(2010) 2085-2089). This is the intended result, once the 1-MCP islocated, for example, inside the headspace of a package containing liveplant material. However, if the cyclodextrin/1-MCP complex is notprotected from exposure to liquid water and/or water vapor prior to theintended use—that is, during processing and storage—the 1-MCP will beprematurely released, and thus much if not all of the effectiveness ofthe complex will be lost prior to arrival at the intended use site.

Additionally, the cyclodextrin/1-MCP complex is heat sensitive, whereinloss of 1-MCP is initiated even in dry environments when the temperaturereaches about 90° C. (Neoh, T. L., et al., J. Phys. Chem. B 2008, 112,15914-15920). Further, in such cases, exposure of released 1-MCP gas toelevated temperatures can lead to an increased risk ofautopolymerization. Thus, there is a need for an improved system ofdelivering plant spoilage retarding materials such as 1-MCP into theheadspaces of plant storage units such that there is not a prematurerelease of the active before it is ready to be used.

While not suffering from the hazards of autopolymerization, othercompounds desirably incorporated into cyclodextrin inclusion complexesfor later release in an end use application, such as fragrances orantimicrobial compounds, suffer from premature loss of the complexedcompounds during processing at elevated temperatures, in the presence ofambient humidity, or both. Additionally, some fragrance or antimicrobialcompounds are not considered useful in conjunction with the cyclodextrincomplex delivery systems described in the art, because of the hightemperatures employed in processing. In such cases, it is specificallynoted that e.g. fragrance molecules having low boiling points must beavoided, since they will be gone by the time the high-temperaturepolymer extrusion processing required to deliver the complex iscompleted. See, e.g. U.S. Pat. No. 7,019,073. Such cyclodextrininclusion complex delivery systems would also benefit from theavailability of a delivery vehicle that provides for an improved yieldof the inclusion complex for availability at the targeted application.

BRIEF SUMMARY OF THE INVENTION

Disclosed herein is a composition that includes, or is substantially, acyclodextrin inclusion complex and a carrier, wherein the cyclodextrincomplex includes a cyclodextrin compound and an olefinic inhibitor, andthe carrier has a melting transition onset between about 23° C. and 40°C. and solubility in water of less than 1 wt % at 25° C. In someembodiments, the cyclodextrin inclusion complex consists ofα-cyclodextrin and 1-methylcyclopropene. In some embodiments, thecarrier has a kinematic viscosity of less than about 30 cP at 100° C. Insome embodiments, the carrier includes, or is substantially onlypetrolatum or a non-petroleum sourced material having properties similarto petrolatum.

Also disclosed herein is a treated substrate. The treated substrateincludes the composition as described above disposed on a substrate. Insome such embodiments, the composition is present in a discontinuouspattern on the substrate. In some embodiments, the treated substrate isa treated laminate. In some embodiments, a container includes thetreated substrate. In various embodiments, the container is enclosed,partially enclosed, or unenclosed. In some embodiments, the containerincludes one or more items of produce. In some embodiments, theatmosphere proximal to the produce comprises between 1 ppb and 5 ppm ofthe olefinic inhibitor.

Also disclosed herein is a method of making a treated substrate. Themethod includes heating the composition described above to a temperaturebetween 60° C. and 80° C., and disposing the heated composition on afirst substrate using a flexographic printing press. In someembodiments, the method further includes cooling the treated substrate,wherein the cooling is accomplished using a chill roll on theflexographic printing press. In some embodiments, the printing isaccomplished using a discontinuous printed pattern. In some suchembodiments, the treated substrate has 50% or less of the availablesubstrate surface area having the composition printed thereon in adiscontinuous printed pattern. In some embodiments, the composition iscontacted with a second substrate after the printing, and optionallyafter the cooling. In some such embodiments, an adhesive is disposedbetween the second substrate and the composition.

Also disclosed herein is a method of printing a printable mediacomposition on a substrate. The printable media composition includes, oris substantially, a cyclodextrin inclusion complex and a printablemedia, wherein the cyclodextrin complex includes a cyclodextrin compoundand a complexed compound, and the printable media has a kinematicviscosity of less than about 30 cP at 100° C. The printing is carriedout by heating the printable media composition to a temperature between50° C. and 100° C., and printing the heated printable media compositionon a first substrate using a flexographic printing press. In someembodiments, the complexed compound is an olefinic inhibitor. Inembodiments, the printing is pattern printing, wherein the pattern is adiscontinuous pattern. In some such embodiments, less than 50% of theavailable surface area of the substrate is printed with thediscontinuous pattern.

Also disclosed herein is the printed substrate obtained by the printingmethod described above. The printed substrate includes the printablemedia composition as described above, flexographically printed on asubstrate. In some embodiments, the printable media composition isflexographically printed in a discontinuous pattern. In someembodiments, the printed substrate is a printed laminate, wherein asecond substrate is disposed over the printable media composition afterthe flexographic printing. In some such embodiments, an adhesive isdisposed between the printable media composition and the secondsubstrate. In some embodiments, a printed container includes the printedsubstrate. In some such embodiments, the printed container is enclosed,partially enclosed, or unenclosed. In some embodiments, the printedcontainer includes one or more items of produce. In some embodiments,the complexed compound is an olefinic inhibitor and the atmosphereproximal to the produce comprises between 1 ppb and 5 ppm of theolefinic inhibitor.

Various embodiments will be described in detail with reference to thedrawings, wherein like reference numerals represent like parts andassemblies throughout the several views. Reference to variousembodiments does not limit the scope of the claims attached hereto.Additionally, any examples set forth in this specification are notintended to be limiting and merely set forth some of the many possibleembodiments for the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway perspective view of an article according to thepresent invention.

FIG. 1A is a cross-section of the article in FIG. 1 taken along line1A-1A of FIG. 1.

FIG. 2 is a perspective view of another article according to the presentinvention.

FIG. 3 is a cross-sectional side view of the article of FIG. 2 takenalong line 3-3 of FIG. 2.

FIG. 4 is a perspective view of another article according to the presentinvention.

FIG. 5 is cross-sectional view side view of the article of FIG. 4 takenalong line 5-5 of FIG. 4.

FIG. 6 is a perspective view of another article according to the presentinvention.

FIG. 7 is a cross-sectional side view of another article according tothe present invention.

FIG. 8 is cross-sectional side view of another article according to thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments will be described in detail with reference to thedrawings, wherein like reference numerals represent like parts andassemblies throughout the several views. Reference to variousembodiments does not limit the scope of the claims attached hereto.Additionally, any examples set forth in this specification are notintended to be limiting and merely set forth some of the many possibleembodiments for the appended claims.

1. Definitions

As used herein, the term “cyclodextrin” or “cyclodextrin compound” meansa cyclomalto-oligosaccharide having at least five glucopyranose unitsjoined by an α(1-4) linkage. Examples of useful cyclodextrins includeα-, β-, or γ-cyclodextrin wherein α-cyclodextrin has six glucoseresidues; β-cyclodextrin has seven glucose residues, and γ-cyclodextrinhas eight glucose residues. Cyclodextrin molecules are characterized bya rigid, truncated conical molecular structure having a hollow interior,or pore, of specific volume. “Cyclodextrin” can also includecyclodextrin derivatives as defined below, or a blend of one or morecyclodextrins compounds. The following table recites properties of α-,β-, and γ-cyclodextrin.

CYCLODEXTRIN TYPICAL PROPERTIES CD PROPERTIES α-CD β-CD γ-CD Degree ofpolymerization (n=) 6 7 8 Molecular Size (A°) inside diameter 5.7 7.89.5 outside diameter 13.7 15.3 16.9 height 7.0 7.0 7.0 Specific Rotation[α]²⁵ _(D) +150.5 +162.5 +177.4 Color of iodine complex Blue YellowYellowish Brown Solubility in Distilled water 14.50 1.85 23.20 (g/100mL) 25° C.

As used herein, the term “cyclodextrin derivative” or “functionalizedcyclodextrin” means a cyclodextrin having a functional group bonded toone of the cyclodextrin glucose moiety hydroxyl groups. Nonlimitingexamples of cyclodextrin derivatives are described in U.S. Pat. No.6,709,746.

As used herein, the term “cyclodextrin inclusion complex” means thecombination of a complexed chemical compound, or “complexed compound”,and a cyclodextrin wherein a complexed compound is disposed within thepore of the cyclodextrin ring. The complexed compound must satisfy thesize criterion of fitting at least partially into the cyclodextrininternal cavity or pore, to form an inclusion complex. The cyclodextrininclusion complexes include, inherent to the formation and existence ofthe inclusion complex, some amount of “uncomplexed” cyclodextrin; thisis because (1) in embodiments synthesis of the inclusion complex doesnot result in 100% formation of inclusion complex; and (2) inembodiments, the inclusion complex is in equilibrium with thecorresponding uncomplexed cyclodextrin/uncomplexed compound. Eachcyclodextrin/compound combination has a characteristic equilibriumassociated with its inclusion complex under a given set of conditions,including temperature, pressure, and humidity conditions. In someembodiments, the complexed compound is an olefinic inhibitor compound.

As used herein, the term “olefinic inhibitor”, “olefinic inhibitorcompound” or “olefinic inhibitor of ethylene generation” is intended tomean an olefinic compound that contains at least one olefinic doublebond, has from about 3 to about 20 carbon atoms and can be aliphatic orcyclic having at least minimal ethylene antagonist or inhibitionactivity.

As used herein, the term “cyclodextrin composition” means a compositionincluding, consisting essentially of, or consisting of a cyclodextrininclusion complex and a hydrophobic carrier.

As used herein, the term “hydrophobic carrier” or “carrier” means acompound or miscible blend of compounds that meets the followingcriteria:

-   1. Melting transition onset of between about 23° C. and 40° C.; and-   2. At least one of the following:    -   a. water contact angle to the carrier surface of 90° or greater,        measured according to ASTM D7334-08 (ASTM International, W.        Conshohocken, Pa.); or    -   b. solubility in water of less than 1 wt % at 25° C.        “Melting transition onset” means a change in the heat capacity        corresponding to the onset of melting, T_(m), the completion of        which corresponds to the complete melting of a material as        indicated by the peak heat capacity. From the integral of this        peak, the enthalpy of melting can be determined; and from the        onset the melting temperature is determined. All measurements of        heat capacity as a function of temperature are measured by        differential scanning calorimetry (DSC). As used herein, “melt        transition onset” means the melt transition onset measured by        DSC over the range −20° C. to 150° C., heating at 10° C./min. In        some embodiments, the carrier has a kinematic viscosity of less        than 30 mm²/s at a temperature of 100° C. In some embodiments,        the carrier includes at least one compound or blend of compounds        that has a chemical structure that is at least 50 mole %        hydrocarbon or dimethylsiloxane. “Hydrocarbon” means consisting        of carbon and hydrogen. “Dimethylsiloxane” means a repeating        unit consisting of —Si(CH₃)₂—O—. In embodiments, the carrier is        characterized by the substantial absence of hydrophilic        compounds, wherein “substantial” means, in this context, that        the presence of hydrophilic compounds is not sufficient to        reduce the water contact angle to below 90°.

As used herein, the term “substrate” means a solid article having atleast one surface capable of receiving a cyclodextrin composition.Substrates are not particularly limited as to makeup, shape, orregarding parameters such as size or thickness. In embodiments, asubstrate includes at least one surface that is suitable for coating orprinting a cyclodextrin composition thereon. Representative examples ofsubstrates include items of produce, thermoplastic or thermoset webs,sheets, and films; metal articles, sheets or foils; glass articles,sheets, or plates; coated or uncoated paper or cardboard articles, websor sheets; combined or multilayer web, sheet, or film constructionsformed from a combination of two or more thermoplastics, thermosets,paper, cardboard, glass, or metals; wrappings, bags, boxes, cartons,punnets, or other articles; articles formed from webs, sheets, films,glass, metals, metal foils, or combinations thereof; wax or filmcoatings; paper or thermoplastic labels, adhesives used to close or sealpackaging or adhere labels and the like thereto; perforated, porous, orpermeable films; open-celled or closed-cell foams; netting or meshformed from cellulosic or thermoplastic materials; fibers, includingcellulosic and synthetic fiber materials, staple fibers, microfibers,and nanofibers, and woven, felted, or nonwoven fabrics formed from thefibers; and the like.

As used herein, the term “container” means a self-contained unit forholding produce, or a component of such a self-contained unit. In someembodiments, a container is also a substrate when employed to receive acyclodextrin composition disposed thereon. In various embodiments,containers are formed from flexible, semi-rigid, or rigid materials, orcombinations thereof. Containers are not particularly limited as tocontent of the material from which they are made, or by parameters suchas overall size, thickness of unit walls or floors, etc. Non-limitingexamples of containers include punnets, dishes, cups, lids, covers,wrapping film, packing foam, sealing tapes, labels, ties, closures,caps, bags, boxes, pouches, envelopes, cartons, netting sacks,refrigerated trucks, shipping containers, warehouse or storage rooms,buildings or sections thereof, and the like. In various embodiments, acontainer defines an enclosed space, such as a sealed bag or aclosed-cell foam; a partially enclosed space, such as a punnet,open-celled foam, or a permeable or perforated bag; or no enclosedspace, such as an open carton or a netting bag.

As used herein, the term “treated substrate” means a substrate having acyclodextrin composition disposed on at least a portion of a surfacethereof.

As used herein, the term “treated laminate” means an article including afirst substrate having a cyclodextrin composition disposed on at least aportion of a surface thereof, and a second substrate disposed over thecyclodextrin composition, wherein the first and second substrates arethe same or different. In some embodiments, the second substrate is notsolid upon contacting the cyclodextrin composition but is solidifiedafter contacting the cyclodextrin composition, such as by cooling orchemical reaction. In general and as determined by context below,discussion of treated substrates include treated laminates. In someembodiments, one of the first or second substrates is removable; in somesuch embodiments, the removable substrate is referred to as a “liner.”

As used herein, the term “treated container” means a container thatincludes a cyclodextrin composition. In embodiments the treatedcontainer includes a treated substrate or a treated laminate. In someembodiments, the treated container is formed from a treated substrate ora treated laminate. In some embodiments the treated container includes atreated substrate as an integral part of the container. In someembodiments, a container is a substrate, and the cyclodextrincomposition is disposed thereon to form the treated container. In someembodiments, a treated substrate or a treated laminate is added to acontainer to form the treated container.

As used herein, the term “article” means a substrate, a container, atreated substrate, a treated container, a treated laminate, or acombination of two or more thereof.

The term “produce” or “produce material” includes any whole plant, plantpart, such as a fruit, flower, cut flower, seed, bulb, cutting, root,leaf, flower, or other material that is actively respiring and, as apart of its maturation, generates ethylene as a maturation hormone(climacteric) or ripens without ethylene and respiration bursts(non-climacteric).

As used herein, the term “permeable” as applied to a cyclodextrincomposition or an article, means that the composition or article has apermeability to the complexed compound of equal to or greater than 0.01(cm³·mm/m²·24 hrs·bar) at standard temperature and pressure (STP) and 0%relative humidity; or permeability to water vapor of equal to or greaterthan 0.1 (g·mm/m²·24 hr) at 38° C. and 90% relative humidity, whenmeasured according to ASTM D96; or permeability to O₂ of equal to orgreater than 0.1 (cm³·mm/m²·24 hr·bar) at 23° C. and 0% relativehumidity, when measured according to ASTM D3985; or permeability to CO₂of equal to or greater than 0.1 (cm³·mm/m²·24 hr·bar) at 23° C. and 0%relative humidity, when measured according to ASTM D1434; or acombination of two or more thereof.

As used herein, the term “impermeable” as applied to a cyclodextrincomposition or an article means that the cyclodextrin composition orarticle has a permeability to the complexed compound of less than 0.01(cm³·mm/m²·24 hrs·bar) at STP and 0% relative humidity; or permeabilityto water vapor of less than 0.1 (g·mm/m²·24 hr) at 38° C. and 90%relative humidity, when measured according to ASTM D96; or permeabilityto O₂ of less than 0.1 (cm³·mm/m²·24 hr·bar) at 23° C. and 0% relativehumidity, when measured according to ASTM D3985; or permeability to CO₂of less than 0.1 (cm³·mm/m²·24 hr·bar) at 23° C. and 0% relativehumidity, when measured according to ASTM D1434; or a combination of twoor more thereof.

As used herein, the term “discontinuous” means having intervals or gaps.As applied to printing operations, discontinuous means a regular orirregular printing pattern having intervals or gaps unprinted by acyclodextrin composition or a printable media composition. In someembodiments other materials—including other printed materials—arepresent in such intervals or gaps, for example; but the other materialsdo not include a cyclodextrin composition or printable mediacomposition.

As used herein, the term “optional” or “optionally” means that thesubsequently described event or circumstance may but need not occur, andthat the description includes instances where the event or circumstanceoccurs and instances in which it does not.

As used herein, the term “about” modifying, for example, the quantity ofan ingredient in a composition, concentration, volume, processtemperature, process time, yield, flow rate, pressure, and like values,and ranges thereof, employed in describing the embodiments of thedisclosure, refers to variation in the numerical quantity that canoccur, for example, through typical measuring and handling proceduresused for making compounds, compositions, concentrates or useformulations; through inadvertent error in these procedures; throughdifferences in the manufacture, source, or purity of starting materialsor ingredients used to carry out the methods, and like proximateconsiderations. The term “about” also encompasses amounts that differdue to aging of a formulation with a particular initial concentration ormixture, and amounts that differ due to mixing or processing aformulation with a particular initial concentration or mixture. Wheremodified by the term “about” the claims appended hereto includeequivalents to these quantities.

As used herein, the term “substantially” means “consisting essentiallyof”, and includes “consisting of”, generally and unless otherwisespecified, as those terms are construed within patent claim language inthe United States as of the date of the filing of this application. Forexample, a solution that is “substantially free” of a specified compoundor material may be free of that compound or material, or may have atrace amount of that compound or material present, such as throughaging, unintended contamination, or incomplete purification. Acomposition that has “substantially only” a provided list of componentsmay consist of only those components, or have trace amounts of one ormore additional components present, or have one or more additionalcomponents present that do not materially affect the properties of thecomposition. And a “substantially planar” surface may have minordefects, or embossed features that do not materially affect the overallplanarity of the film.

2. Cyclodextrin Compositions and Treated Substrates

We have found that one or more cyclodextrin inclusion complexes areuseful to form a cyclodextrin composition using mild conditions. Inembodiments, the cyclodextrin compositions are disposed on at least aportion of a surface of a substrate to form a treated substrate. Inother embodiments, the cyclodextrin compositions are disposed on atleast a portion of a surface of a first substrate and a second substrateis disposed over the cyclodextrin composition to form a treatedlaminate. In embodiments, a treated substrate or a treated laminate iseither included in, or is used to form a treated container.

The cyclodextrin compositions of the invention include at least acyclodextrin inclusion complex and a carrier. The cyclodextrin employedto form the cyclodextrin inclusion complex is selected for the specificvolume of the cyclodextrin pore. That is, the cyclodextrin pore size isselected to fit the molecule size of the compound used to complex withthe cyclodextrin. In embodiments, the complexed compound is an olefinicinhibitor. The olefinic inhibitor is a compound having from 3 to about20 carbon atoms, comprising at least one olefinic bond and a cyclic,olefinic or diazodiene structure. In some embodiments, the olefinicinhibitor has the following structure:

wherein each of R¹, R² are independently hydrogen or a C₁₋₁₆ hydrocarbylgroup and R³ and R⁴ are independently hydrogen or a C₁₋₁₆ hydrocarbylgroup with the proviso that at least one of R¹ or R² is methyl.

Representative examples of compounds useful as the olefinic inhibitor ofethylene generation include 1-methyl cyclopropene, 1-butene, 2-butene,and isobutylene. Of these, 1-methyl cyclopropene, or “1-MCP”, has beenfound to be particularly useful. It has been found that 1-MCP has amolecular size that is suitable for formation of an inclusion complexwhen combined with α-cyclodextrin, or α-CD.

In embodiments, the inclusion complex of α-CD with 1-MCP, or“1-MCP/c/α-CD”, contains about 0.10 to 0.99 mole of the olefinicinhibitor per mole of cyclodextrin, or about 0.20 to 0.95 mole of theolefinic inhibitor per mole of cyclodextrin, or about 0.30 to 0.90 moleof the olefinic inhibitor per mole of cyclodextrin, or about 0.50 to0.90 mole of the olefinic inhibitor per mole of cyclodextrin, or about0.50 to 0.80 mole of the olefinic inhibitor per mole of cyclodextrin, orabout 0.30 to 0.70 mole of the olefinic inhibitor per mole ofcyclodextrin, or any combination of the above listed value ranges, forexample, about 0.70 to 0.80 mole of the olefinic inhibitor per mole ofcyclodextrin, 0.90 to 0.95 mole of the olefinic inhibitor per mole ofcyclodextrin, 0.10 to 0.20 mole of the olefinic inhibitor per mole ofcyclodextrin, and the like.

In other embodiments, the complexed compound is an antimicrobialcompound. Examples of antimicrobial compounds usefully complexed withcyclodextrin, most commonly but not exclusively β-cyclodextrin, includechlorine dioxide, ethanol, triclosan(5-chloro-2-(2,4-dichlorophenoxy)phenol), amyl phenol, phenyl phenol,catechin, p-cresol, hydroquinones, benzyl-4-chlorophenol, short chainalkyl parabens, short chain alkyl esters of p-hydroxybenzoic acid,3,4,4′-trichlorocarbanilide, benzoic anhydride, sorbic anhydride,octanal, nonal, cis-2-hexenal and trans-2-hexenal,2,2-diphenyl-1-picrylhydrzyl, organic acids such as acetic acid,propanoic acid, benzoic acid, citric acid, lactic acid, malic acid,propionic acid, sorbic acid, succinic acid, and tartaric acid as well assalts thereof, such as calcium sorbate, potassium sorbate, and sodiumbenzoate; hexamethylenetetramine, silicon quaternary ammonium salts,phosphoric acid, chitosan and chitooligosaccharides, Konjac glucomannan,Natamycin, Reuterin, peptides such as Attacin, Cecropin, Defensin, andMagainin; antioxidants such as butylated hydroxyanisole (BHA), phenolicbutylated hydroxytoluene (BHT), and t-butylhydroquinone (TBHQ);bacteriocins such as Bavaricin, Brevicin, Carnocin, Imazalil, Lacticin,Mesenterocin, Nisin, Pediocin, Propolis, Sakacin, and Subtilin;chelators such as citrates, conalbumin, EDTA, lactoferrin, andpolyphosphates; essential oils such as cinnamon bark oil, citron oil,coriander oil, eucalyptus oil, lavender oil, lemon grass oil, peppermintoil, perilla oil, rosemary oil, tea oil, Ajwain oil, basil oil, carawayoil, citronella oil, coriander oil, clove oil, Fenugreek oil, gingeroil, mustard oil, oregano (oreganum) oil, paprika oil, and thyme oil;fatty acids and esters thereof, wherein fatty acids include lauric acid,palmitoleic acid, and monolaurin and fatty acid monoesters includeglycerol monolaurate, glycerol monocaprate, propylene glycolmonolaurate, and propylene glycol monocaprate; fungicides such asBenomyl, Imazalil, and sulfur dioxide; methyl-(glucocapparin),ethyl-(glucolepidiin), propyl-(glucoputranjivin),n-butyl-(glucocochlearin), allyl-(sinigrin), metals such as copper andsilver; allyl isothiocyanate (AIT), camphor, carvacrol, cineole,cinnamaldehyde, citral, p-cymene, estragole (methyl chavicol), eugenol,geraniol, geranyl acetate, hinokitiol (β-thujaplicin), limonene,linalool, p-menthone, menthol, neral, perillaldehyde, α-pinene,γ-terpinene, terpineol, thymol, mixtures of two or more thereof, and thelike.

In other embodiments, the complexed compound is a fragrance compound.Usefully complexed fragrance compounds include compounds such as amylcyanamid, benzyl salicylate, amyl cinnamic aldehyde, citral,benzophenone, cedrol, cedryl acetate, dihydroisojasmonate, diphenyloxide, patchouli alcohol, musk ketone, and the like, but lower-boilingcompounds such as certain low-boiling essential oils and lower estersare also useful in embodiments.

In still other embodiments, the compositions of the invention include amixture of complexed compounds that include one or more fragrancecompounds and one or more antimicrobial compounds. In still otherembodiments, the compositions of the invention include a mixture ofcomplexed compound that include an olefinic inhibitor and anantimicrobial compound. Due to the ease of forming the cyclodextrincomplexes, the ease of forming the compositions, and the ease of usingthe compositions by disposing them on one or more substrates, suchblended and multiple use compositions are easily envisioned and employedby one of skill in any ratio suitable for a targeted application.

Methods employed to form cyclodextrin inclusion complexes are known andare found in the literature. Typical methods involve admixing thecyclodextrin and the compound to be complexed in aqueous solution for aperiod of time sufficient to form the inclusion complex. However, theuse of 1-MCP or other low-boiling olefinic inhibitors as the complexedcompound involves adjustment of the methodology to account for the needto complex cyclodextrin with a gas at common ambient temperatures (1-MCPhas a boiling point of 12° C.). The inclusion complex of α-cyclodextrinand 1-MCP, also referred to herein as “1-MCP/c/α-CD”, is known, andmethod of forming it are described, for example, in U.S. Pat. Nos.6,017,849 and 6,548,448 as well as in Neoh, et al., J. Agric. Food Chem.2007, 55, 11020-11026. In one method, α-cyclodextrin is dissolved inwater and 1-MCP is bubbled into the solution for a period of time atroom temperature. The inclusion complex precipitates from the solutionas it forms and thus is easily isolated by simple filtration followed byvacuum drying. The dried cyclodextrin inclusion complex is then readyfor use. Storage in a dry container with minimal head space issufficient.

In some embodiments, a cyclodextrin inclusion complex is formed with acyclodextrin derivative. Cyclodextrin derivatives are employed to formthe inclusion complex in some embodiments to improve miscibility in thecyclodextrin composition. Cyclodextrin derivatives employed to improvemiscibility of the cyclodextrin composition include any of thecyclodextrin derivatives described in U.S. Pat. No. 6,709,746 or inCroft, A. P. and Bartsch, R. A., Tetrahedron Vol. 39, No. 9, pp.1417-1474 (1983). In some embodiments where a cyclodextrin derivative isemployed to form the cyclodextrin inclusion complex, the olefinicinhibitor is introduced in a non-water solvent, for example ahydrocarbon having 1 to 10 carbons, an alcohol having 1 to 10 carbons, aheterocyclic or aromatic solvent having 4 to 10 carbons. In some suchembodiments, blends of one or more solvents are employed. In otherembodiments, the inclusion complex is formed prior to functionalizationof the cyclodextrin derivative. In such embodiments, care must be takenduring the functionalization to employ techniques and select functionalgroup chemistries that avoid displacing the olefinic inhibitor from theinclusion complex, for example by preferential inclusion of one of thecompounds employed in the functionalization.

The cyclodextrin composition is an admixture of the cyclodextrininclusion complex and a hydrophobic carrier. The carrier is defined by alow melting point and high hydrophobicity. The carrier is a compound ormiscible blend of compounds that meets the following criteria:

-   -   1. Melting transition onset of between about 23° C. and 40° C.,        as measured by DSC at 10° C./min between −20° C. and 150° C.;        and    -   2. One or more of the following:        -   a. water contact angle to the carrier surface of 90° or            greater, measured according to ASTM D7334-08 (ASTM            International, W. Conshohocken, Pa.);        -   b. solubility in water of less than 1 wt % at 25° C.

The melting transition onset of the carrier is between about 23° C. and40° C. when measured by DSC by subjecting the carrier to a temperaturerange of −20° C. to 150° C., heating at 10° C. per minute; in someembodiments the melting transition onset is between about 23° C. and 38°C., or between about 23° C. and 36° C., or between about 23° C. and 34°C., or between about 25° C. and 38° C., or between about 25° C. and 36°C., or between about 25° C. and 35° C. In some embodiments, the watercontact angle of the carrier surface is between about 80° and 160°, orbetween about 90° and 120°. The carrier has solubility in water of lessthan 1 wt % at 25° C., for example about 0.0001 wt % to 0.99 wt % at 25°C., or about 0.001 wt % to 0.90 wt % at 25° C., or about 0.01 wt % to0.75 wt % at 25° C., or about 0.01 wt % to 0.50 wt % at 25° C., or about0.01 wt % to 0.10 wt % at 25° C., or about 0.0001 wt % to 0.10 wt % at25° C.

In some embodiments, the carrier has a kinematic viscosity of less than30 mm²/s at a temperature of 100° C., for example a dynamic viscosity ofbetween 1 cP and 30 cP at 100° C., or between 1 cP and 30 cP at 90° C.

In some embodiments, the carrier includes at least one compound or blendof compounds that has a chemical structure that is at least 50 mole %hydrocarbon or dimethylsiloxane. In some embodiments, the carrierconsists essentially of a compound or blend of compounds that has achemical structure that is at least 50 mole % hydrocarbon ordimethylsiloxane. In various embodiments, the hydrocarbon compoundsinclude alkyl, alkenyl, or alkynyl moieties, or a mixture thereof;linear, branched, or cyclic moieties, or a mixture thereof; aliphatic,or aromatic moieties, or a mixture thereof; and in embodiments is ablend of two or more such hydrocarbon compounds. “Dimethylsiloxane”means a repeating unit consisting of

In various embodiments, the dimethylsiloxane is a linear or cycliccompound or a blend thereof, wherein n in the structure shown above isat least 3. Where the dimethylsiloxane is linear, the chain terminationis hydrogen, hydroxyl, alkyl, aryl, or alkaryl. In embodiments, thechemical structure is about 50 mole % to 100 mole % hydrocarbon ordimethylsiloxane, or about 60 mole % to 99 mole % hydrocarbon ordimethylsiloxane, or about 70 mole % to 98 mole % hydrocarbon ordimethylsiloxane, or about 80 mole % to 95 mole % hydrocarbon ordimethylsiloxane, or about 90 mole % to 99 mole % hydrocarbon ordimethylsiloxane. In some embodiments, the carrier includes at least onecompound or blend of compounds that has a chemical structure that is atleast 50 mole % hydrocarbon. In some embodiments, the carrier consistsessentially of a compound or blend of compounds that has a chemicalstructure that is 50 mole % to 100 mole % hydrocarbon, or about 60 mole% to 99 mole % hydrocarbon, or about 70 mole % to 98 mole % hydrocarbon,or about 80 mole % to 95 mole % hydrocarbon, or about 90 mole % to 99mole % hydrocarbon, or about 95 mole % to 99 mole % hydrocarbon, orabout 98 mole % to 100 mole % hydrocarbon.

In some embodiments, a suitable carrier includes petrolatum or consistsessentially of petrolatum. Petrolatum (Merkur; mineral jelly; petroleumjelly; CAS No. [8009-03-8]; EINECS No. 232-373-2) is a purified mixtureof semisolid saturated hydrocarbons having the general formulaC_(n)H_(2n+2), and is obtained from petroleum sources. The hydrocarbonsconsist mainly of branched and unbranched chains although some cyclicalkanes and aromatic molecules with alkyl side chains may also bepresent. Petrolatum is manufactured from the semisolid residue thatremains after the steam or vacuum distillation of petroleum. Thisresidue is dewaxed and/or blended with stock from other sources, alongwith lighter fractions, to give a product with the desired consistency.Final purification is typically performed by a combination ofhigh-pressure hydrogenation or sulfuric acid treatment followed byfiltration through adsorbents. A suitable antioxidant is added in somecases.

The rheological properties of petrolatum are determined by the ratio ofthe unbranched chains to the branched chains and cyclic components ofthe mixture. Petrolatum contains relatively high amounts of branched andcyclic hydrocarbons in contrast to paraffin, which accounts for itssofter character. It has been shown by both rheological andspectrophotometric methods that petrolatum undergoes a melting phasetransition onset between 23° C. and 40° C., depending on the specificblend of compounds in the mixture. Because petrolatum is a mixture, thephase transition occurs over a broad range, often between about 25° C.and 65° C., or about 30° C. and 60° C., or about 35° C. and 60° C. Inembodiments, petrolatums have cone penetration of above 100 dmm and lessthan 275 dmm (ASTM D937).

Animal studies have shown petrolatum to be nontoxic and noncarcinogenicin both subcutaneous and oral dosing. Petrolatum is a GRAS material, isincluded in the U.S. FDA Inactive Ingredients Guide, and is accepted foruse in food applications in many countries worldwide.

In some embodiments, a suitable carrier includes or consists essentiallyof a petrolatum-like material that is sourced from vegetable matter.Such materials are described, for example, in U.S. Pat. No. 7,842,746.The vegetable based petrolatum-like materials are made from hydrogenatedpolymerized vegetable oils, such as hydrogenated blown oils orhydrogenated copolymerized oils. The petrolatum-like materials areformulated to have a targeted range of properties and thus are suitablyformulated to have melting transition onset of between about 23° C. and40° C., as well as water contact angle to the surface of 90° or greater,measured according to ASTM D7334-08, and/or solubility in water of lessthan 1 wt % at 25° C., either alone or in a blend with one or moreadditional components.

In some embodiments, the carrier is characterized by the substantialabsence of hydrophilic compounds, wherein “substantial” means, in thiscontext, either that the presence of any hydrophilic compounds is notsufficient to reduce the water contact angle of the carrier to below90°, or that the presence of any hydrophilic compounds is not sufficientto increase the water solubility of the carrier to more than 1 wt % at25° C. In other embodiments, the carrier is characterized by thesubstantial absence of hydrophilic compounds. The nature and chemicalstructure of “hydrophilic compounds” is not particularly limited butincludes any compound that, when added to the carrier, causes the watercontact angle of the carrier to decrease, or the water solubility of thecarrier to increase, or both. Surfactants, humectants, superabsorbents,and the like are examples of hydrophilic compounds that are added, insome embodiments, to the carrier for example to increase compatibilitywith a substrate, scavenge water from the carrier during processing, orsome other purpose.

In embodiments, components included in the carrier are waxes, polymers,nucleating agents, oils, solvents, water scavengers, desiccants,adhesion promoters, antifouling agents, thermal or oxidativestabilizers, colorants, adjuvants, plasticizers, crosslinkers, or twomore thereof. Components are not generally limited in nature and aredictated by the particular end use of the cyclodextrin compositions andtreated substrates, further within the boundaries for the carrierproperties set forth above.

In some embodiments, waxes are employed in the carrier. Waxes arehydrophobic compounds having melting points, or melting transitiononsets, of over 40° C., for example between about 40° C. and 200° C., orbetween about 50° C. and 170° C., or between about 60° C. and 150° C.,or between about 70° C. and 120° C. Hydrophobic means having solubilityin water of less than 1 wt % at 25° C. Suitable waxes include paraffinwax, animal waxes, vegetable waxes, mineral waxes, synthetic waxes,bayberry wax, beeswax, microcrystalline wax, stearyl dimethicone,stearyl trimethicone, ethylene-α-olefin copolymers, C₁₈-C₄₅ olefins, andethylene or propylene oligomers and short chain homopolymers as well ascopolymers thereof. In some embodiments, the wax is a nucleating agentthat improves the solidification “set time” of the carrier upon cooling,if the cyclodextrin composition is heated e.g. for blending or in orderto coat it on a substrate. Nucleating agents include short chainpolyolefin waxes of ethylene, propylene, or both, that are polymerizedusing Fischer-Tropsch catalysts or other specialized catalysts in orderto induce high density (over 0.95 g/cm³) and high crystalline content inthe solid wax.

In some embodiments, oils are included in the carrier. Oils arehydrophobic compounds that are liquids at 25° C. Hydrophobic meanshaving solubility in water of less than 1 wt % at 25° C. In someembodiments, the oil is a hydrocarbon or silicone oil; in otherembodiments the oil is a plant oil such as peanut oil, walnut oil,canola oil, linseed oil, and the like. In some embodiments, the oil is a“drying oil”, that is, the oil reacts with oxygen in the atmosphere toform crosslinks. In embodiments, one or more oils are added to thecarrier at about 0.1 wt % to 50 wt % of the weight of the carrier, orabout 0.5 wt % to 25 wt % of the weight of the carrier, or about 1 wt %to 10 wt % of the weight of the carrier.

In some embodiments, a combination of one or more of a polymer, a wax,petrolatum, and an oil are employed, together with one or moreadditional components to form the carrier meeting the criteria formelting transition onset and hydrophobicity as set forth above. In someembodiments, a wax and an oil, petrolatum and a wax, petrolatum and anoil, or a combination of a wax, petrolatum, and an oil areadvantageously employed to form the carrier meeting the criteria formelting transition onset and hydrophobicity as set forth above. In otherembodiments, a wax or petrolatum alone meet the criteria for meltingtransition onset and hydrophobicity as set forth above.

In some embodiments, water scavengers are included in the carrier. Awater scavenger is a compound that is soluble or dispersible in thecarrier, and is available to react preferentially with water moleculessuch that it effectively acts to scavenge ambient moisture from airbornehumidity during standard processing conditions including admixing andapplication of the composition to a substrate. The amount of waterscavenger added should be a minimum amount to react with ambientmoisture during processing. This is because, during some intended usesof the cyclodextrin composition, water is required to facilitate releaseof the complexed compound into the environment. Thus, an amount of waterscavenger should be provided in the cyclodextrin composition that isquickly depleted once a substantial amount of water vapor or liquidwater is encountered. Examples of water scavengers suitably employed inthe cyclodextrin compositions of the invention include various orthoesters and hexamethyldisilazane. In embodiments, about 1 wt % or less ofthe water scavenger based on the total cyclodextrin composition weightis added to the carrier, for example about 0.01 wt % to 1 wt % of thecarrier or about 0.05 wt % to 0.5 wt % of the carrier.

In some embodiments, desiccants are employed in the carrier. In otherembodiments, desiccants are employed elsewhere in conjunction with thetreated substrates. For example, in some embodiments where thecyclodextrin inclusion complex is 1-MCP/c/α-CD, desiccants are useful toscavenge water from the interior of an enclosed volume into which arespiring produce material is expected to generate an excess of thedesired amount of water needed for release of 1-MCP. In someembodiments, “excess water” means sufficient water vapor that 100%relative humidity is exceeded and liquid water is condensed within theenclosed volume. The effects of excess water are described in moredetail below. Desiccants are also added, in some embodiments, directlyto the interior of a treated container, or to a treated laminateseparately from the cyclodextrin composition itself; however, in someembodiments, the desiccant is added directly into the carrier forconvenience and/or efficiency. Examples of desiccants that are suitablyemployed include silica gel, activated charcoal, calcium sulfate,calcium chloride, montmorillonite clay, and molecular sieves. The amountof desiccant incorporated within the carrier is not particularly limitedand is selected based on the particular end use, that is, amount ofambient humidity or liquid water expected in the end use, whether theapplication involves an enclosed volume, partially enclosed volume, oran unenclosed volume, and the like. In general, the amount of desiccantis selected to be about 0.001 wt % to 99 wt % based on the total weightof the cyclodextrin composition, or about 0.1 wt % to 50 wt % based onthe total weight of the cyclodextrin composition, or about 1 wt % to 10wt % based on the total weight of the cyclodextrin composition.

In embodiments, the cyclodextrin composition is formed by admixing thecarrier with the cyclodextrin inclusion complex. In some suchembodiments, the admixing is carried out at an elevated temperature,which in this context means a temperature greater than 20° C. In somesuch embodiments, the admixing is carried out under dry conditions. Inthis context, “dry” means the carrier, and any gaseous environmentsurrounding the carrier during processing and formation of thecyclodextrin composition, has less than 250 ppm of water, for exampleabout 0.01 ppm to 250 ppm water, or about 0.1 ppm to 200 ppm water, orabout 1 to 100 ppm of water. In some embodiments, the gaseousenvironment has less water than the carrier due to the ease of providinga dry gaseous environment as will be appreciated by the skilled artisan.In some embodiments, both elevated temperature and dry conditions areemployed. The elevated temperature employed in the mixing is less than90° C. when the inclusion complex is 1-MCP/c/α-CD, because 90° C. is theonset temperature triggering loss of 1-MCP from the inclusion complex.In some embodiments where 1-MCP is not the complexed compound, i.e.where the complexed compound is a fragrance or antimicrobial compound orset of compounds, a temperature above 90° C. is employed. The elevatedtemperature is employed to provide ease of mixing, due to the loweredviscosity of the carrier. In the case of 1-MCP/c/α-CD, the mixing iscarried out between 20° C. and 90° C., or between about 30° C. and 80°C., or between about 40° C. and 75° C., or between about 60° C. and 75°C.

In embodiments, dry conditions are employed in connection with both thecarrier and the surrounding environment during the admixing of thecyclodextrin composition. The surrounding environment includes, invarious embodiments, air, nitrogen, argon, CO₂, or any other gasselected and includes a partial vacuum insofar as adsorbed water remainspresent e.g. on vessel surfaces. In some embodiments, the amount ofwater present in the carrier at 20° C. is between about 10 and 50 ppm offree water (water not taken up by a scavenger or a desiccant), or about10 ppm to 80 ppm of free water at 30° C., or about 10 ppm to 200 ppm offree water at 50° C. In some embodiments, the surrounding gaseousenvironment includes about 4 ppm to 17 ppm water at 20° C., or about 7ppm to 30 ppm water at 30° C., or about 10 ppm to 45 ppm water at 40°C., or about 15 ppm to 70 ppm water at 50° C.

In embodiments, the amount of cyclodextrin inclusion complex employed inthe cyclodextrin composition is about 0.001% by weight to 25% by weightof the composition, or about 0.01% by weight to 10% by weight of thecomposition, or about 0.05% by weight to 5% by weight of thecomposition. The amount of cyclodextrin inclusion complex included in aparticular formulation is selected based on the volume of thesurrounding environment and the concentration of complexed compounddesired in the environment, in conjunction with the permeability of thecarrier to water, permeability of the carrier to the complexed compound,and presence of a second substrate if the treated substrate is a treatedlaminate. Criteria informing this selection are described in greaterdetail below.

In some embodiments where the treated substrate is a treated laminate,one or both of the first or second substrates includes one or moredesiccants. In some such embodiments the desiccants are embedded in, oradhered to, the one or more substrates. In some such embodiments, one ofthe first or second substrates is a liner, that is, a removal substrate;in some such embodiments the desiccant is employed along with the linerto exclude water during storage and/or shipping. The liner is removedupon arrival of the treated substrate to its use destination, whereuponatmospheric moisture is available to trigger release of the complexedcompound present in the cyclodextrin complex. The desiccant is attachedto the liner in such a manner that it remains substantially attached tothe liner when the liner is removed from the treated substrate.

Substrates usefully employed to form the treated substrates of theinvention include any substrate suitable for disposition of thecyclodextrin composition on at least a portion of a surface thereof. Insome embodiments, the substrate surface is the surface of a plate, film,or sheet and thus is substantially planar and well suited for continuousindustrial coating operations. In other embodiments, the cyclodextrincomposition is disposed on a non-planar substrate surface or anirregular substrate surface to form a treated substrate. In someembodiments, the substrate is a container. Suitable substrates includecellulosic and other natural and synthetic biomass-based substrates, aswell as synthetic petroleum-based thermoplastic polymeric films, sheets,fibers, or woven, felted, or nonwoven fabrics, and composite materialsincluding one or more thereof. Some examples of substrates usefullyemployed to form treated substrates, including treated containers andtreated laminates, include paper, paperboard, cardboard, cartonboardsuch as corrugated cardboard, coated paper or cardboard such asextrusion coated paper or cardboard, chipboard, nonwoven, felted, orwoven fabrics, wood, netting, wood/thermoplastic composites, glass,metals, polyvinyl halides such as poly(vinyl chloride) (plasticized andunplasticized) and copolymers thereof; polyvinylidene halides such aspolyvinylidene chloride and copolymers thereof; polyolefins such aspolyethylene, polypropylene, copolymers thereof, and morphologicalvariations thereof including LLDPE, LDPE, HDPE, UHMWPE, metallocenepolymerized polypropylene, and the like; polyesters such as polyethyleneterephthalate (PET) or polylactic acid (PLA) and plasticized variationsthereof; polystyrene and copolymers thereof including HIPS; polyvinylalcohol and copolymers thereof; copolymers of ethylene and vinylacetate; and the like. Blends, alloys, composites, crosslinked versionsthereof, and recycled versions thereof are also useful in variousembodiments. Two or more layers of such substrates are present in someembodiments as multilayer films or carton constructions. In someembodiments, the substrates are substantially continuous. In someembodiments the substrates are permeable, porous, microporous,perforated, meshed, foamed (open- or closed-cell) nonwoven fabrics, orare netting.

The substrates contain, in some embodiments, one or more fillers,stabilizers, colorants, and the like. In some embodiments the substrateshave one or more surface coatings thereon. In some embodiments thesubstrate has a surface coating thereon prior to coating thecyclodextrin composition. Surface coatings include protective coatingssuch as wax, acrylic polymer, vinyl acetate/ethylene copolymer andethylene/vinyl chloride copolymer coatings, and the like; coatings torender surfaces printable; coatings to render otherwise permeablesubstrates impermeable; adhesive coatings; primers; tie layer coatings;metalized or reflective coatings; and the like. The type and function ofsurface coatings are not particularly limited within the scope of thisdisclosure; likewise the manner in which the surface coatings areapplied is not particularly limited. In various embodiments where asurface coating will be exposed to an enclosed or partially enclosedvolume within a produce package, the surface coating is subsequentlycoated with the cyclodextrin composition.

In some embodiments, the substrate is polyethylene extrusion coatedrecyclable paperboard, corrugated cardboard, or carton board packaging,for shipment of produce. Printed paperboard or corrugated cardboardpackaging ranges from bulk bins to specialized display cartons. Theextrusion coated surface provides an opportunity to dispose acyclodextrin composition thereon.

In some embodiments the substrate is pretreated with a plasma or coronatreatment prior to disposing the cyclodextrin composition thereon. Suchsurface treatments are well known in the industry and are often employedin the industry to modify the surface energy of substrates, for exampleto improve wetting or adhesion of coatings or printed materials to thesurface of a substrate. Such surface treatments are likewise useful insome embodiments to improve wetting and adhesion of the cyclodextrincompositions to the substrate.

In some embodiments, the substrate is treated with a primer prior todisposing the cyclodextrin composition thereon. In some such embodimentsfilms and sheets of thermoplastics used as substrates are obtained orpurchased already pre-coated with a primer; a wide variety of such filmsand sheets are available in the industry and are targeted for improvingadhesion of various types of coatings thereto. In some embodiments aplain film or sheet is coated “in line” with a primer. A plethora ofsuch coatings and technologies are available and one of skill willunderstand that primer coatings are optimized for each application andfor the composition to be disposed thereon. Some examples of primercompositions suitably disposed between the substrate surface and thecyclodextrin compositions include polyethyleneimine polymers such aspolyethyleneimine, alkyl-modified polyethyleneimines in which the alkylhas 1 to 12 carbon atoms, poly(ethyleneimineurea), ethyleneimine adductsof polyaminepolyamides, and epichlorohydrin adducts ofpolyaminepolyamides, acrylic ester polymers such as acrylamide/acrylicester copolymers, acrylamide/acrylic ester/methacrylic ester copolymers,polyacrylamide derivatives, acrylic ester polymers containing oxazolinegroups, and poly(acrylic ester)s. In embodiments, the primer compositionis an acrylic resin, a polyurethane resin, or mixture thereof.

An alternative method to treat or “prime” materials is via a glowdischarge using either corona or atmospheric plasma. Both methods aretypically used in an air atmosphere but other gases or gas mixtures canalso be used and may include, and not limited to, oxygen, nitrogen,argon, helium, carbon dioxide, ammonia, water vapor, etc. The glowdischarge treatment has the ability to “clean” material surfaces byremoval of contaminants and to create polar moieties on surfaces. Insome embodiments, such treatments promote adhesion of disposed materialsthereto, uniformity of disposed coatings, or both. Examples of coronaand plasma systems are those available from Enercon Industries(www.enerconind.com), Vetaphone (www.vetaphone.com), and Plasmatreat(www.plasmatreat.com). Advantages of corona and plasma treatmentinclude: a) there is no need to add another chemical to the substrate,b) there is no need for drying or post curing of the substrate, c) glowdischarge is a highly efficient process from gas utilization efficiency,and d) such processes are well aligned with sustainability guidelinesregarding product, occupational and environmental safety.

In some embodiments where the cyclodextrin composition includes anolefinic inhibitor, the substrate is a sheet or film that is formed intoa container suitable to hold produce within an enclosed space, apartially enclosed space, or an unenclosed space. In other embodimentsthe substrate is a sheet or film that is converted into coupons, strips,tabs, and the like for the purpose of insertion into an otherwiseuntreated container. In still other embodiments, the substrate is atreated laminate. In some embodiments, the treated laminate is permeableto the olefinic inhibitor on a first side thereof and is impermeable tothe olefinic inhibitor on a second side thereof. In some embodiments,the substrate is a treated laminate that is permeable to water on atleast a first side thereof. In some embodiments coupons, strips, tabs,and the like are labels that are adhesively applied to produce or acontainer. In some such embodiments, the coupons, strips, tabs, and thelike are labels that are further printed with one or more indicia. Thecyclodextrin composition is present, in various embodiments, on anysurface that is directly or indirectly exposed to the produce; theexposure is within an enclosed space, a partially enclosed space, or anunenclosed environment. One of skill will appreciate that the amount ofcyclodextrin inclusion complex in the cyclodextrin composition, thecomposition of the carrier, and the amount of cyclodextrin compositiondisposed in the vicinity of the produce will be varied in response tothe substrate employed, type of produce, enclosed vs. unenclosed natureof the environment surrounding the produce, and the expected temperatureand amount of water vapor encountered during use.

In some embodiments where the cyclodextrin composition includes anolefinic inhibitor, the cyclodextrin composition is directly disposed onproduce, for example as a continuous or discontinuous coating, or aspart of an adhesive or in printed characters on a printed or reverseprinted produce label. In such embodiments, all or a portion of thecoating or label contains the cyclodextrin composition.

In some embodiments, the treated substrate is incorporated within apersonal care product. For example, a cyclodextrin composition having acyclodextrin inclusion complex of a fragrance compound or anantimicrobial compound is used to form a treated fiber. The treatedfiber is incorporated into a nonwoven sheet that is then formed into awipe, a diaper, a feminine protection article, or the like. In anotherexample, a cyclodextrin composition having a cyclodextrin inclusioncomplex of a fragrance compound is used to form a treated laminate. Thetreated laminate is incorporated into a tape article. Such tape articlesare useful for a personal hygiene article, for example. In someembodiments, the one of the substrates employed to form the laminate isa removable liner. Upon removal of the liner, the fragrance is releasedslowly. Such removable-liner tape articles are useful for householdfragrance release, for example to mount on a wall, or on a cat litterbox, or near a diaper pail. In some embodiments, the liner is sectionedso that removal can be sequential, or two or more sections are removedat once, depending on the preference of the end user.

Because of the low temperature, dry conditions that are employed to formthe articles, a high yield of the antimicrobial or fragrance propertiesare retained in the treated substrates when the end user triggers thestart of the release of the selected complexed compound from thecyclodextrin composition. Similarly, in the case of 1-MCP or anotherolefinic inhibitor, a high yield of olefinic inhibitor is retained inthe treated substrates after processing.

In embodiments, the yield of cyclodextrin complex on the treatedsubstrate is at least 95 wt % of the weight of the cyclodextrin complexadded to the carrier, for example about 95 wt % to 100%, or about 96 wt% to 99.99 wt %, or about 97 wt % to 99.9 wt %, or about 98 wt % to 99wt %, or about 98 wt % to 100%, or about 98 wt % to 99.99 wt %, or about99 wt % to 99.9 wt %, or about 99 wt % to 99.99 wt % of the cyclodextrincomplex added to the carrier. The exact percent yield will depend on thetemperature of processing vs. the inherent equilibrium of thecyclodextrin inclusion complex—including the volatility of the complexedcompound, and the amount of water present during the processing, both inthe carrier and in the surrounding environment.

Treated laminates include constructions having a cyclodextrincomposition disposed between a first major surface of a first substrateand a second major surface of a second substrate. The second substrateis the same or different from the first substrate. In some suchembodiments, the first or second substrate is the substrate from which acontainer is formed. In such embodiments, the cyclodextrin compositionis generally not in direct contact with e.g. the interior of a treatedcontainer, or with produce, or other items; that is, it is disposedsubstantially between the first and second substrates. In someembodiments where the cyclodextrin composition includes an olefinicinhibitor, at least one of the first and second substrates is permeableto water, and at least one of the first and second substrates ispermeable to the olefinic inhibitor. In some such embodiments, the firstsubstrate is permeable to the olefinic inhibitor and the secondsubstrate is impermeable to the olefinic inhibitor. In some suchembodiments, the first substrate is permeable to water vapor and thesecond substrate is impermeable to water vapor. In some suchembodiments, the second substrate is permeable to water vapor and thefirst substrate is impermeable to water vapor.

3. Methods of Making the Treated Substrates

In some embodiments, the cyclodextrin compositions are disposed onto thesurface of a substrate by a coating technique. Coating is accomplishedusing several known coating technologies available in the industry. Insome embodiments coating is accomplished without employing elevatedtemperatures, that is, by employing ambient temperatures of a processingfacility. In other embodiments, the temperature during disposing isbetween about 20° C. and 90° C., or between about 40° C. and 80° C. Insome embodiments, coating is carried out under dry conditions, employingconditions that are the same or substantially similar to the dryconditions described above.

Useful coating techniques employed to coat the cyclodextrin compositionsinclude, for example, die coating, slot coating, curtain coating, floodcoating, gap coating, notch bar coating, wrapped wire bar drawdowncoating, dip coating, brush coating, spray coating, pattern coating suchas rotogravure coating, and print coating employing printingtechnologies such as flexographic printing, inkjet printing,lithographic printing techniques, letterset printing, and screenprinting. Viscosity of the cyclodextrin composition, the shape andcomposition of the substrate or produce, and the desire to coat theentirety vs. a portion of a surface dictates which of the known coatingtechnologies are useful to coat the cyclodextrin compositions. Forexample, die coating, slot coating, notch bar coating, and the like areusefully employed to coat the entirety of a substantially planar web ofsubstrate, whereas in embodiments where only a portion of a surface isto be coated, or coating onto a formed container or onto produce isdesirable, one or more spray, dip, or print coating technologies isdesirably employed. In some embodiments where a specific portion of asubstrate is to be coated, or where a patterned coating is desired,print coating or rotogravure coating is desirably used.

We have found that flexographic printing techniques are particular wellsuited for use in conjunction with the cyclodextrin compositions todeliver a highly precise and reproducible amount of cyclodextrincomposition to a substrate. Where the substrate is a sheet or film,great cost efficiency is realized by employing large scale continuousflexographic printing of the cyclodextrin compositions. The rheologicalprofile of the carrier employed in the cyclodextrin compositions issurprisingly well suited for this production method; and the hydrophobicnature of the selected carrier material protects the cyclodextrininclusion complex from ambient water vapor that results in prematureloss of the complexed compound. Where the complexed compound is 1-MCP,prevention of premature loss is of critical importance for large scaleproduction. This is because where large amounts of 1-MCP are released,as is potentially the case in a large scale production scenario, therisk of autopolymerization is maximized. The autopolymerization of 1-MCPis known to be a violent, explosive reaction and must therefore beavoided. Further, is has been established that the onset temperature forloss of 1-MCP from 1-MCP/c/α-CD is 90° C. The ability to coat (print)the cyclodextrin composition containing 1-MCP/c/α-CD under dryconditions and at temperatures below 90° C. thus provides a safe meansfor large scale production. Other complexed compounds havecharacteristic onset temperatures of release, and the low temperaturesemployed in both forming and printing the cyclodextrin compositions ofthe invention are advantageous from the standpoint of delivering maximumyield of intact cyclodextrin inclusion complex to the intended substratefor use in the intended application. Flexographic printing also impartsthe ability to deliver a highly precise and reproducible amount ofcyclodextrin composition to a substrate, resulting in the maximumefficiency in terms of controlled release. Where the complexed compoundis 1-MCP, this further translates to a more consistent distribution of1-MCP in and around the produce, which in turn results in consistentpreservation of the produce. Consistency in distribution of 1-MCP is arecognized problem in the industry that is easily solved using thisapproach. Finally, we have found that the hydrophobic carrier employedin the approach provides a predictable, reproducible, and consistentrate of release of the complexed compound during use and in the presenceof water vapor or liquid water or both. Again, where the complexedcompound is 1-MCP, the consistency is critical for solving the knownproblem of inconsistent 1-MCP distribution within groupings of produce,wherein in employing the approaches of the prior art, some producewithin a container would appear to receive a sufficient amount of 1-MCP,and thus be preserved satisfactorily, and some would appear to receiveeither an insufficient amount of 1-MCP or none at all.

Flexography is a form of relief printing wherein a liquid ink is appliedto an elastomeric surface, called a plate, on which the image is raisedabove the rest of the surface as a 3D positive relief. It is aweb-based, continuous process that employs a series of cylinders, orrolls, to transfer ink to a substrate. In a typical flexographicprocess, a flexographic ink is applied in a uniform layer to the raisedportions of the flexographic plate mounted on a cylinder, or roll, viaan ink metering cylinder, called an anilox roll, and the ink is thentransferred from the flexographic plate onto a continuously movingsubstrate via a series of rolls. The inks typically employed are eitherquick drying, such as a solvent based ink, or are radiation curable.

Flexography is used most commonly to apply graphic images or labeling tosubstrates such as packaging films or sheets in a continuous process,wherein conversion of the films or sheets is carried out after theprinting. A wide range of substrates are conveniently and easilyaddressed in flexographic printing. Examples of substrates commonlyaddressed include a wide range of thermoplastic films such aspolyethylene, polypropylene, polyester, and nylon films, foils, coatedand uncoated paper, paperboard, and corrugated board. In some instances,even nonwoven webs are printed using flexographic printing techniques.Ease of use makes flexography an ideal printing method for manypackaging and labeling uses.

Another feature of flexographic printing is that the technique lendsitself to application of multiple layers. While only one color can beapplied per flexographic plate for example, three, four, or more plateprinting combinations are easily built into flexographic lines in serialfashion in order to build full color images in a single pass. Further,application of a laminated top film layer or a printed top layer, suchas a UV curable clearcoat, for protective purposes is easilyincorporated within a flexographic operation. One lamination approacheasily incorporated into the flexographic process involves applicationof a UV curable adhesive to a first, flexographically printed substrate,followed by application of a transparent second substrate to theadhesive and curing of the adhesive that is accomplished by UVtransmission through the second substrate. In some such embodiments, theapplication of the adhesive is also accomplished by a flexographicprinting process.

Additionally, the techniques employed to make flexographic plates lendthemselves readily to providing a precise amount of material to asubstrate in a repeating pattern or a continuous pattern. Further,flexographic printing is achievable at very high speeds, up to about2000 ft/min or about 600 meter/min, with high precision. Finally,digital, direct-to-plate engraving using laser imaging to removeflexographic plate layers has enabled the use of higher durabilitymaterials than were accessible using the traditional photopolymerimaging methods of plate generation, which further improves the alreadyeconomically favorable profile of large scale flexographic printingprocesses by greatly extending plate life. The laser imaging methodretains the tight tolerances, measured in tenths of thousandths of aninch, of the photopolymer imaging method; these tolerances are necessaryfor high quality, precision flexographic printing.

Chill rolls used in the flexographic printing industry provide webcooling after the ink is transferred to the substrate. In suchembodiments, after printing, the web is passed over a chill roll,wherein contact with the chill roll is made with the major side oppositethe printed side. Cooling the web retards ink smearing and helps reduceweb temperature before the next printing station, in order to assureproper registration of the next printed layer. This is of particularimportance in operations where heat, whether added to remove solvent orproduced by UV curing of inks, has insufficient time to dissipate duringhigh speed continuous runs.

The flexographic printing industry is divided into two sectors,delineated by the printing press width: wide web presses, over about 470mm wide, that address applications such as flexible packaging, sacks,pre-print and disposables; and narrow web presses, below 470 mm wide,that are used both for shorter runs and for narrow web applications suchas pressure sensitive labels, paperboard cartons, corrugated packaging,and narrow web flexible packaging.

While any of the substrates listed in the sections above are suitablyaddressed in flexographic printing operations, one area addressedcommonly and conveniently in flexographic applications is flexiblepackaging. Flexible packaging is formed from substrates of tenmillimeters or less wherein the shape of the substrate is readilychanged. Common flexible packaging substrates include, for example,polyolefin and polyester films wherein printing is carried out on one orboth major surfaces of a substantially flat web as it is unwound from aroll source. A large proportion of printing and labeling of flexiblepackaging, including bar code labeling for example, is carried out usingflexographic processes. An industry shift from rigid to flexiblepackaging has also resulted in an increase in the use of flexographicprinting and labeling of packaging materials for fresh produce, snackfoods, drugs, surgical and medical products, pet food, agriculturalproducts, and industrial chemicals.

The cyclodextrin compositions are suitably applied to any substrate thatcan be printed using flexographic printing processes. Since the carrieremployed in the cyclodextrin compositions has a kinematic viscosity ofless than 30 mm²/s at 100° C., the flexographic printing is suitablecarried out by heating the cyclodextrin compositions to temperatures of90° C. and below, for example between about 60° C. and 80° C., orbetween about 50° C. and 70° C. At these temperatures, we have foundthat the cyclodextrin compositions print cleanly and precisely usingstandard flexographic conditions including high line speed. For example,the line speeds achievable using flexographic printing of thecyclodextrin compositions at temperatures below 90° C. are about 10meters per minute (m/min) to 600 m/min. In embodiments the minimum linespeed is about 30 m/min, or about 40 m/min, or about 50 m/min, or about60 m/min, or about 75 m/min, or about 100 m/min, or about 150 m/min, orabout 200 m/min, or about 250 m/min, or about 300 m/min, or about 400m/min, wherein the maximum line speed is about 600 m/min in any selectedembodiment.

Further, the cyclodextrin compositions are easily kept dry while in asealed container awaiting flexographic printing on a production line. Inthis way, long term storage issues encountered in some applications,that is, the need to keep the cyclodextrin composition dry, is obviated.Thus, the premature loss of the complexed compound is avoided and highyield of the cyclodextrin inclusion complex is realized. As is discussedabove, this is advantageous for all cyclodextrin compositions, but is ofcritical importance in the case of low boiling olefinic inhibitors andin particular in the case of 1-MCP, due to its tendency toautopolymerize.

In some embodiments, after printing and downweb in a flexographicprinting press, a chill roll is employed to reduce the temperature ofthe cyclodextrin composition on the substrate. In some such embodiments,the chill roll is employed at a temperature wherein the contact time ofthe chill roll with the substrate is sufficient to lower the temperatureof the cyclodextrin composition to at or below the melting transitiononset of the carrier. Use of the chill roll is advantageous where theflexographic process, or another coating process, involves elevatedtemperatures to lower the viscosity of the cyclodextrin compositionduring the disposing on the substrate, but insufficient coolingotherwise occurs between the disposing and a subsequent step inprocessing the treated substrate. In some embodiments, lowering thetemperature of the cyclodextrin composition to below the meltingtemperature of the carrier prevents the running, transferring, orsmearing of the cyclodextrin composition in subsequent printing or otherprocessing steps. In embodiments, the chill roll is set to a temperatureof about −100° C. to 10° C., or about −80° C. to 0° C. Agents employedto lower the temperature of the chill roll are known to those havingskill, but include, for example, ice, dry ice, and combinations thereofof with solvents, salts, and the like; or a liquid such as water, analcohol, ethylene glycol or another glycol, a mixture of one or morethereof, or another liquid or mixture, such as an anti-freeze mixture,that is circulated between the chill roll and a refrigeration apparatus.

In some embodiments, after the cyclodextrin composition is disposed onthe substrate to form the treated substrate, the treated substrate isfurther processed to form a treated laminate. In such embodiments, thetreated substrate is a treated first substrate. The treated firstsubstrate is further laminated with a second substrate to form thetreated laminate. In some such embodiments, the second substrate is athermoplastic film coated with a pressure sensitive adhesive, whereinthe treated laminate is formed by contacting the first substrate on theprinted side thereof with the second substrate on the adhesive sidethereof. In some embodiments, pressure is further applied to the treatedlaminate, for example by passing the treated laminate through a niproll, in order to more firmly affix the second substrate to the firstsubstrate. In such embodiments, the second substrate is not particularlylimited in terms of the material employed, and the material may beselected, for example, to provide targeted permeability to water, thecomplexed compound, or both. In some such embodiments the secondsubstrate includes, by way of example, paper, a nonwoven, or athermoplastic film; in some embodiments the thermoplastic film isporous, microporous, permeable, impermeable, or perforated.

In other embodiments, a treated laminate is formed by applying a UVcurable (polymerizable and/or crosslinkable) adhesive, also referred toas a laminating adhesive, directly to the first substrate afterflexographically printing the cyclodextrin composition thereon, and asecond substrate is wet laminated to the uncured adhesive by applyingthe second substrate employing a nip. The adhesive is then cured byirradiating through the second substrate, typically very close to thenipped wet lamination point. Thus, in such embodiments, it is necessarythat the second substrate be at least partially transparent to the UVwavelength range employed in the curing process. In some embodiments, alaminating adhesive coating thickness of about 2 μm to 15 μm is appliedvia flexographic printing, using about 100 to 2000 lines/cm. The UV lampis mounted proximal to the nip point where the film is laminated toprevent separation or air pockets from forming in the laminatedsubstrate. The skilled artisan will appreciate that the adhesive cureconditions are adjusted to provide sufficient and optimal cure; linespeed, bulb energy (mJ per unit of area), and thickness of the adhesivelayer are common variables, for example. In some embodiments, a curableadhesive is cured via electron beam (e-beam) in similar fashion to theUV curing process, but employing an e-beam instead of UV light. In suchembodiments, the need to add a photoinitiator is obviated.

The desired amount of the cyclodextrin composition disposed per unit ofarea of a treated substrate, whether by flexographic printing or by someother technique, is not particularly limited within the scope of thecomposition. The desired amount per unit area of the cyclodextrincomposition is a function of both the thickness of a layer disposed onthe substrate, and whether or not the layer is a continuous ordiscontinuous layer. Continuous layers are commonly deposited by coatingtechniques such as knife coating, curtain coating, spray coating, andthe like; discontinuous or patterned layers are commonly deposited byprinting techniques such as gravure, screen, flexographic, or inkjetprinting. While it is not necessary to limit the thickness of either acontinuous or a discontinuous coating to a single thickness, inpracticality this is most often selected for economy. While thethickness of the cyclodextrin composition disposed on the substrate islimited in some embodiments by the technique employed in disposing it,the thickness is further selected based on the amount of cyclodextrininclusion complex in the cyclodextrin composition, the inherentequilibrium ratio of the cyclodextrin inclusion complex with uncomplexedcompound, the permeability of the carrier to the uncomplexed compound,the permeabilities of the first and second substrates if the treatedsubstrate is a treated laminate, the surface area selected to receivethe cyclodextrin composition, and the amount of the uncomplexed compoundthat is desirably present in the environment surrounding the treatedsubstrate. Where the compound is an olefinic inhibitor, the amount ofthe uncomplexed compound that is desirably present in the environmentsurrounding the treated substrate, also referred to herein as the“effective amount”, is based on the type of produce selected forolefinic inhibitor exposure, the volume of the enclosed, partiallyenclosed, or unenclosed space surrounding the produce, and the expectedconditions of temperature and humidity. It is a feature of thecyclodextrin compositions that such amounts are selected with ease,wherein the amounts of olefinic inhibitor released are predictable,reproducible and consistent.

In some embodiments, the thickness of a continuous or discontinuouscyclodextrin composition layer, disposed on a treated substrate, isbetween about 0.01 micrometer (μm) and 5 millimeter (mm) thick, orbetween about 0.1 μm and 1 mm thick, or between about 0.5 μm and 0.05 mmthick; however, as stated above, the thickness of a continuous ordiscontinuous cyclodextrin composition layer is not particularly limitedand is selected for one or more criteria including, for example, theselected technique of disposing the cyclodextrin composition, the amountof cyclodextrin inclusion complex included in the cyclodextrincomposition, the rheological profile of the composition, the totalsurface area selected for the disposing, and the continuous ordiscontinuous nature of the coating.

In embodiments, the treated substrates include discontinuous coatings ofthe cyclodextrin compositions disposed on the substrates, wherein thediscontinuous printed coating covers between about 0.1% and 99% of theavailable surface area of the substrate, or about 1% to 90%, or about 2%to 80%, or about 5% to 70%, or about 10% to 60%, or about 20% to 50% ofthe available surface area of a substrate; in some embodiments, thediscontinuous printed coating covers between 0.1% and 99% of theavailable surface area of the substrate in any range therein inintervals of 0.1% of the surface area, for example between 55.3% and58.9%, or between 40.3% and 40.4%, or between 0.5% and 1.0%, or between0.8% and 22.7%; it is a feature of the invention that the amount ofcyclodextrin composition deposited on the surface of the substrate iseasily controlled to such an extent by employing the methods of theinvention to print discontinuous patterns of the cyclodextrincompositions on a variety of substrates as described herein.

In some embodiments, the cyclodextrin complex is blended with aprintable media to form a printable media composition, wherein theprintable media composition is printable using flexographic printing.Printable media compositions include, consist essentially of, or consistof a cyclodextrin complex and a printable media. A printable media is amaterial or blend of materials that is a solid at or below about 30° C.and has a kinematic viscosity of less than 30 mm²/s at 100° C. Anymaterial or blend of materials meeting these requirements is suitable asa printable media for flexographic printing and suitable for use in aprintable media composition. The printable media composition includes atleast the printable media and a cyclodextrin complexed with a complexedcompound. The complexed compounds useful in the printable mediacompositions are the same as those described above, that is, an olefinicinhibitor, a fragrance, or an antimicrobial molecule; blends ofcyclodextrin complexes are also suitably employed in the printable mediacompositions.

In embodiments of the printable media composition where the complexedcompound is 1-MCP, it is necessary that the printable media have akinematic viscosity of less than 30 mm²/s at 90° C., and preferable thatthe printable media be provided and maintained in a dry condition duringaddition of the cyclodextrin complex to form the printable mediacomposition as well as during printing of the printable mediacomposition onto one or more substrates using flexographic printing.

Examples of useful printable media include, by way of non-limitingexamples, lower molecular weight polyalkylene oxides, including linearand branched adducts thereof, endcapped adducts thereof, and copolymersthereof such as polyethylene oxide-polypropylene oxide block copolymers;hydrocarbon, fluorocarbon, or silicone waxes; fatty acids and estersthereof; salt hydrides; and blends of these, as well as blends of thesewith one or more additional components.

In various embodiments, additional components usefully included in theprintable media are any of the materials disclosed above as componentsof the hydrophobic carrier. Thus, petrolatum or materials having similarproperties thereto, polymers, nucleating agents, oils, solvents, waterscavengers, desiccants, adhesion promoters, antifouling agents, thermalor oxidative stabilizers, colorants, adjuvants, plasticizers,crosslinkers, or two more thereof are included in various embodiments ofthe printable media. Additional components are not generally limited innature and are dictated by the particular end use of the printable mediacompositions and treated substrates formed by printing the printablemedia compositions onto one or more substrates, further within theproperty boundaries for the printable media properties set forth above.

In some embodiments, waxes are employed as the printable media, eitheralone or in a blend with other components. Waxes useful in the printablemedia are hydrophobic or hydrophilic compounds generally having lowmolecular weights and having melting points, or melting transitiononsets, between about 40° C. and 200° C., or between about 50° C. and150° C., or between about 50° C. and 120° C., or between about 50° C.and 100° C. Suitable waxes include polyalkylene oxide waxes, paraffinwax, animal waxes, vegetable waxes, including hydrogenated polymerizedoils such as those described in U.S. Pat. No. 7,842,746, mineral waxes,synthetic waxes, bayberry wax, beeswax, microcrystalline waxes, alkyldimethicones, alkyl trimethicones, lower ethylene-α-olefin copolymers,C₁₈-C₄₅ olefins, and ethylene or propylene oligomers and short chainhomopolymers as well as copolymers thereof. In some embodiments, the waxis a nucleating agent that improves the solidification “set time” of theprintable media upon cooling, if the printable media composition isheated e.g. for blending or in order to coat it on a substrate.Nucleating agents include short chain polyolefin waxes of ethylene,propylene, or both, that are polymerized using Fischer-Tropsch catalystsor other specialized catalysts in order to induce high density (over0.95 g/cm³) and high crystalline content in the solid wax.

In some embodiments, microcrystalline waxes are employed in theprintable media. In embodiments, microcrystalline waxes have meltingpoints ranging from 54° C. to about 102° C. They have needle penetrationof above 3 dmm and less than 100 dmm (ASTM D1321). Viscosities arehigher than 5 cP at 100° C. In some embodiments, the microcrystallinewax is petroleum based. In other embodiments, the microcrystalline waxis vegetable based, for example a hydrogenated polymerized oil such as avegetable based wax described in U.S. Pat. No. 7,842,746. Also describedin U.S. Pat. No. 7,842,746 are vegetable based petrolatum-likematerials, which are similarly useful in the printable media as acomponent thereof.

In some embodiments, oils are included in the printable media. Oils arehydrophobic or hydrophilic compounds that are liquids at 25° C. and insome embodiments are combustible and have viscosities greater than about5 cP at 25° C. In some embodiments, the oil is a synthetic hydrocarbonor silicone oil; in other embodiments the oil is a plant oil such aspeanut oil, walnut oil, canola oil, linseed oil, and the like. In someembodiments, the oil is a “drying oil”, that is, the oil reacts withoxygen in the atmosphere to form crosslinks. In some embodiments, theoil is an essential oil.

In embodiments, a printable media composition is printed onto asubstrate using flexographic printing to form a printed substrate. Theterm “substrate” is defined above; “printed substrate” means a substratehaving a printable media composition disposed thereon by flexographicprinting. In all other respects, a printed substrate is the same as atreated substrate as that term is used elsewhere herein; and the printedsubstrate is used in the same applications and in the same way as thetreated substrates as described elsewhere herein. It is an advantage offlexographic printing methodology that discontinuous patterns, such asdiscrete “islands” containing the printable media compositions, areeasily formed using flexographic printing of the printable mediacompositions.

In embodiments, the printed substrates include discontinuous coatings ofthe printable media compositions disposed on the substrates, wherein thediscontinuous printed coating covers between about 0.1% and 99% of theavailable surface area of the substrate, or about 1% to 90%, or about 2%to 80%, or about 5% to 70%, or about 10% to 60%, or about 20% to 50% ofthe available surface area of a substrate; in some embodiments, thediscontinuous printed coating covers between 0.1% and 99% of theavailable surface area of the substrate in any range therein inintervals of 0.1% of the surface area, for example between 55.3% and58.9%, or between 40.3% and 40.4%, or between 0.5% and 1.0%, or between0.8% and 22.7%; it is a feature of the invention that the amount ofprintable media composition deposited on the surface of the substrate iseasily controlled to such an extent by employing the methods of theinvention to print discontinuous patterns of the printable mediacompositions on a variety of substrates as described herein.

In some embodiments, the printed substrate is a printed laminate,wherein the printable media composition is printed onto a firstsubstrate, and a second substrate is disposed over the printable mediacomposition after the printing. In all other respects, the printedlaminate is the same as a treated laminate, as that term is usedelsewhere herein; and the printed laminate is used in the sameapplications and in the same way as the treated laminates as describedelsewhere herein.

In some embodiments, the printed substrate is a printed container,wherein the term “container” is defined above; “printed container” meansa container having a printable media composition disposed thereon byflexographic printing. In embodiments the printed container includes aprinted substrate or a printed laminate. In some embodiments, theprinted container is formed from a printed substrate or a printedlaminate. In some embodiments the printed container includes a printedsubstrate as an integral part of the container. In some embodiments, acontainer is a substrate, and the printable media composition is printedthereon to form the printed container. In some embodiments, a printedsubstrate or a printed laminate is added to a container to form theprinted container. In all other respects, the printed container is thesame as that term is used elsewhere herein; and the printed container isused in the same applications and in the same way as the treatedcontainers as described elsewhere herein.

4. Methods of Using the Treated Substrates

The treated substrates, treated laminates, and treated containers areusefully employed in a number of applications. Where the cyclodextrincomposition includes a fragrance, the treated substrates, treatedlaminates, and treated containers are usefully employed in householdfragrance applications including household perfume release, vacuumcleaner bag fresheners, odor releasing wipes, cat litter box fresheners,garbage can fresheners, car perfume release articles, and the like.Where the cyclodextrin composition includes an antimicrobial, thetreated substrates, treated laminates, and treated containers areusefully employed in flexible food packaging films, labels, disposablework surface films, personal care products, comestible containers,bedding, wipes, medical products such as bandaging, medical drapes, andmedical clothing for slow release of antimicrobial compounds. In someembodiments, the treated substrates, treated laminates, and treatedcontainers are usefully formed to contain both fragrance andantimicrobial compounds for slow and controlled release, since incertain articles a combination thereof is advantageous.

Where the cyclodextrin composition includes an olefinic inhibitor, thetreated substrates, including treated laminates and treated containers,are usefully employed in the inhibition of maturation or ripening ofproduce. In some embodiments, the treated substrates are usefullyincluded within the enclosed volume of packaged produce. In embodiments,the treated substrate is arranged such that the cyclodextrin compositioncontacts the interior atmosphere of the enclosed volume surrounding oneor more produce items, the enclosed volume being provided by thecontainer. The type and conformation of the produce container is notparticularly limited; any bag, box, punnet, carton, tub, cup, pallet,bag, transportation interior (e.g. truck interior), etc. that defines anenclosed space usefully employs the treated substrates. Ambienthumidity, humidity from produce respiration, added liquid water or watervapor, or a combination of two or more thereof provide the necessarywater that triggers release of the olefinic inhibitor from thecyclodextrin inclusion complex.

In other embodiments, the treated substrate is arranged such that thecyclodextrin composition contacts the atmosphere surrounding a partiallyenclosed or unenclosed volume near one or more produce items, or withinor nearby a partially enclosed or unenclosed container. In some suchembodiments, the container is a treated container, but in otherembodiments the container is not a treated container and the treatedsubstrate is provided outside the container but in proximity thereto. Insuch embodiments, the proximity is simply determined by whether aneffective concentration of the olefinic inhibitor is provided in theatmosphere surrounding the produce, taking into account the amount ofcyclodextrin composition, amount of liquid water or water vapor presentin the atmosphere, the degree of partial enclosure, and the type ofproduce. The type and conformation of the produce container is notparticularly limited; any bag, box, carton, punnet, tub, cup, pallet,bag, transportation interior (e.g. truck interior), building area, gatedoutdoor area, etc. that defines a partially enclosed space or anunenclosed space usefully employs the treated substrates. Ambienthumidity, humidity from produce respiration, added liquid water or watervapor, or a combination of two or more thereof provide the necessarywater that triggers release of the olefinic inhibitor from thecyclodextrin inclusion complex.

The surface area and thickness of the cyclodextrin composition exposedto the interior of a produce container is selected to provide a suitableatmospheric (gaseous) concentration of the olefinic inhibitor to theenclosed space such that the useful life of the produce is optimized.The selection process is discussed in more detail below. Factorsaffecting the provision of the optimum atmospheric concentration ofolefinic inhibitor include the type of produce being addressed, theamount of cyclodextrin inclusion complex in the cyclodextrincomposition, the amount of cyclodextrin composition present on thetreated substrate, the inherent equilibrium ratio of the cyclodextrininclusion complex with uncomplexed olefin inhibitor, the permeability ofthe carrier to the olefinic inhibitor, the permeability of the substrateor substrates to the olefinic inhibitor, the viscosity or coatingthickness requirements of the technique employed to coat thecyclodextrin composition, the volume of the enclosed, partiallyenclosed, or unenclosed space surrounding the produce that will beaddressed, and the amount of liquid or gaseous water expected within thesame volume, included ambient humidity and water vapor generated bytranspiration of the plant material.

In some embodiments, the treated substrate is simply a sheet or filmbearing a coating, such as a slot coating or flexographically printedcoating, of the cyclodextrin composition; in other embodiments thetreated substrate is a treated laminate. In some such embodiments theamount of complexed compound required for a particular application isestimated based variables such as the desired level of the complexedcompound in the atmosphere, the volume of atmosphere to be addressed,and the amount of water amount expected. Then based on the total coatedvolume of cyclodextrin composition per unit area of the treatedsubstrate, the substrate is divided—for example, by cutting the treatedsubstrate—to a selected size that delivers the correct amount ofcyclodextrin composition. In other embodiments, uniform sections arepre-cut and one, two, or more sections are selected to provide a totalselected coated amount of cyclodextrin composition.

In such calculations, the value of delivering a targeted coating amountto the targeted volume is realized. Certain embodiments described aboveare particularly advantageous in delivering a precisely measured amountof cyclodextrin composition to an enclosed, partially enclosed, orunenclosed volume, as well as enabling delivery of an easily variedamount of cyclodextrin composition to a target container. For example,flexographic printing is well understood to deliver precise and easilyvaried volumes of material to substrates over an easily varied surfacearea of a variety of substrates. Another advantage of using printingtechniques to deliver the cyclodextrin compositions is that printing iseasily incorporated into a production assembly line setup for packagingmaterials and other industrially and commercially useful formats andthus provides a convenient and economical means for building a deliveryvehicle for release of complexed compounds from the cyclodextrincompositions, whether applied directly on a container, or on a label, aclosure, or within a laminate applied to a container, on a treatedsubstrate added to a container, within a treated laminate included in anopen area, or the like.

In some embodiments where the complexed compound is an olefinicinhibitor, the substrate used to make a treated substrate employs anadditional means to control the amount of water (vapor and/or liquid)enclosed within a container while further in the presence of the producematerial. While the amount of water in a package's enclosed space is ofconcern from the standpoint of release of an olefinic inhibitor from thecyclodextrin compositions of the invention, it is well known that veryhigh levels of moisture in a package containing produce material is alsoseparately detrimental to certain moisture sensitive produce (berries,citrus, lettuce, mushrooms, onions, and peppers, for example). Excessmoisture triggers various physiological disorders in some postharvestfruits and vegetables, shortening shelf life and quality. In particular,liquid water in the form of condensation on produce material surfaceshastens spoilage and considerably shortens storage life. In someembodiments, internal humidity controllers (humectants and desiccants)are incorporated into porous sachets, within the substrate of theinvention, or even within the cyclodextrin compositions themselves inconjunction with a treated substrate. In embodiments, humiditycontrollers help maintain optimum in-package relative humidity (about85% to 95% for cut fruits and vegetables, for example), reduce moistureloss from the produce material itself, and/or prevent buildup of excessmoisture in headspace and interstices where microorganisms can grow. Theamount of olefinic inhibitor incorporated within the packaging structurewill be different in packaging having excess water as contrasted bylower humidity packaging of low transpiration postharvest products.Therefore, to operate the technology a number of factors (chemical andbiological) will be considered to manufacture optimum packagingstructures and bulk shipping containers for different groups ofpostharvest products.

In embodiments where the complexed compound is an olefinic inhibitor,treated substrates are useful in embodiments where modified atmospherepackaging (MAP), equilibrium modified atmosphere packaging (EMAP), orcontrolled atmosphere packaging (CAP) is employed. The objective in MAPis to provide a desired atmosphere around produce by providing a sealedcontainer having controlled permeability to oxygen and carbon dioxide,resulting in an improvement in produce quality when compared to airstorage. Typically, the permeability of the container changes withtemperature and partial pressures of each gas exterior to the container.The objective in CAP is to displace some or all of the atmospheric aircomposition (78% N₂, 21% O₂) within the container with e.g. carbondioxide or nitrogen or a blend of two or more gases in a desiredproportion. A number of patents set forth various features of MAP andCAP. U.S. Pat. No. 7,601,374 discusses both approaches and alsoreferences a substantial list of other patents issued for various MAPand CAP technologies. It will be appreciated that the cyclodextrincompositions find further utility in conjunction with MAP, CAP, ortechnologies that combine features of both approaches. In someembodiments, the cyclodextrin compositions are employed directly,wherein the MAP, EMAP, or CAP substrates are employed as treatedsubstrates; in other embodiments, treated substrates are added to theMAP, EMAP, or CAP packages, e.g. as inserts.

MAP is a useful approach for maintaining improved flavored fruits andvegetables by minimizing development of off-flavors due to fermentativemetabolism or odor transfer from fungi or other sources. MAP isrecognized to improve resistance to postharvest stresses, decay andother plant disorders. An ‘active package’ having a modified atmosphereintegrated with the controlled release of an olefinic inhibitor asdelivered by the cyclodextrin compositions of the invention will improvethe quality of fresh-cut fruits and vegetables for consumers includingsingle-serve, ready-to-eat packaging and containers for vendingmachines. In an exemplary embodiment of the invention, MAP or CAP isused in conjunction with the treated substrates of the invention forlarge polyethylene bags employed to packaging pallets of cartons,wherein the cartons contain fresh produce. Such pallet-size bags arewidely employed for shipment of pallets of produce, supported incartons; the bags are employed for the purpose of enclosing the producein a modified or controlled atmosphere during shipping. In some suchembodiments, the bags, the paperboard (e.g. polyethylene extrusioncoated paperboard) cartons, labels on the cartons or the bag, a treatedinsert, or a combination of two or more thereof include a treatedsubstrate of the invention.

EMAP is a method to help prolong the shelf life of fresh produce byoptimizing the in-package equilibrium atmosphere. This is achieved bymodifying the permeability of the packaging film. Film micro-perforationis one way to regulate the equilibrium concentrations of O₂ and CO₂.Micro-perforated films are apertured films or otherwise rendered porous,by puncturing or by stretching a film made from a mixture of athermoplastic material and particulate filler. These films permit thetransfer only by molecular gas/vapor diffusion and block the transfer ofliquid. Examples of microporous or micro-perforated films includeFRESHHOLD® film, available from River Ranch Technology, Inc. of Salinas,Calif.; P-PLUS® film, available from Sidlaw Packaging of Bristol, GreatBritain and described in U.S. Pat. Nos. 6,296,923 and 5,832,699; andfilms from Clopay Plastic Products Co. of Mason, Ohio described in U.S.Pat. Nos. 7,629,042 and 6,092,761.

Additionally, in embodiments where the complexed compound is an olefinicinhibitor, treated substrates are useful in embodiments where gaspermeability of non-perforated and nonporous films is modified by simplymanufacturing films of different thicknesses or using the selectivity ofhydrophilic films produced from segmented block copolymers, andemploying these materials as substrates in conjunction with thecyclodextrin compositions. Segmented block copolymers or multi-blockcopolymers consist of alternating flexible soft segments andcrystallizable rigid segments. The properties of segmented blockcopolymers are varied by changing the block lengths of the flexible(soft) and rigid segments. Rigid and flexible segments arethermodynamically immiscible and, therefore, phase separation occurs.The rigid segments crystallize and form lamellae in the continuous softphase. Rigid segments can contain ester, urethane or amide groups, whilethe flexible segments are usually polyesters or polyethers—poly(ethyleneoxide) (PEO) and/or more hydrophobic poly(tetramethylene oxide) (PTMO).In breathable film, the gas vapor is transported mainly through the softphase; selective gas permeability depends on the density of thehydrophilic groups in the polymer, the relative humidity, and thetemperature.

In embodiments where the complexed compound is an olefinic inhibitor,treated substrates are useful in embodiments where specialized andselectively permeable substrates are employed. One example of aselectively permeable substrate is BreatheWay® packaging, currently usedin conjunction with fresh-cut produce marketed by Apio, Inc. ofGuadalupe, Calif. (www.breatheway.com; also see www.apioinc.com).BreatheWay® films are selectively permeable membranes that controlinflux of oxygen and outflux of carbon dioxide in order to provideadjusted O₂/CO₂ ratios to extend shelf life. The membranes are alsotemperature responsive. While such packaging provides improved O₂/CO₂ratios for extending shelf life of respiring produce, it does nototherwise inhibit ripening of the produce. Examples of other suitablebreathable hydrophilic films include PEBAX®, a thermoplastic polyamidemanufactured by Total Petrochemicals USA, Inc. of Houston, Tex.;SYMPATEX®, a breathable hydrophilic polyether-ester block copolymermanufactured by SympaTex Technologies GmbH of Unterföhring, Germany;HYTREL®, a thermoplastic polyester elastomer manufactured by DuPontdeNemours and Co. of Wilmington, Del.; and segmented polyurethanes suchas ELASTOLLAN® (ELASTOGRAN®) and PELLETHANE®, supplied by Dow Chemicalsof Midland, Mich. These polymers have a large, selective gaspermeability range. The cyclodextrin compositions, in conjunction withsuch permeable membrane technology, represent a complete solution toextended shelf life of respiring produce.

It will be appreciated that the articles and applications describedabove benefit in a number of ways from the advantages offered by thecompositions and methods described herein. The cyclodextrin inclusioncomplexes are easily formed and isolated using mild conditions whereinhigh yields of inclusion complex formation are realized. Thecyclodextrin inclusion complexes are easily stored until added to acyclodextrin composition. The cyclodextrin compositions are easilyformed and coated using mild conditions. The cyclodextrin compositionsare easily stored or can be formed and used in a production line. Avariable and precise amount of cyclodextrin composition is easily andreproducibly added to a variety of substrates, and laminates andcontainers are easily addressed. A variety of easily implemented methodsof delivering the cyclodextrin compositions are possible, andflexographic printing is a particularly useful methodology to deliver avariable and precise amount of cyclodextrin composition to a variety ofsubstrates rapidly and economically. The treated substrates of theinvention are useful in a wide variety of applications for slow andcontrolled release of the complexed compounds within the cyclodextrininclusion complexes.

5. 1-Methylcyclopropene (1-MCP) as the Olefinic Inhibitor

In embodiments where the cyclodextrin inclusion complex includes theolefinic inhibitor 1-MCP, the effective amount of cyclodextrincomposition disposed on the treated substrate is selected to provide anatmospheric (gaseous) concentration of 1-MCP to the enclosed, partiallyenclosed, or open volume surrounding the selected produce such that theuseful life, or “shelf life”, of the produce is extended over the shelflife of the produce in the absence of the cyclodextrin composition. Aneffective amount of 1-MCP in the environment within the enclosed,partially enclosed, or unenclosed surrounding the produce is betweenabout 1 part per billion (ppb) to about 10 parts per million (ppm), orbetween about 5 ppb and 5 ppm, or between about 10 ppb and 3 ppm, orbetween about 50 ppb and 2 ppm, or between about 100 ppb and 1 ppm, orbetween about 25 ppb and 1 ppm, or between about 50 ppb and 500 ppb, orany intermediate range between 1 ppb and 10 ppm in any increment of 10ppb, such as 10 ppb to 50 ppb, 100 ppb to 500 ppb, and the like; it is afeature of the invention that such ranges are realistically andaccurately targeted using the cyclodextrin compositions.

In embodiments the 1-MCP cyclodextrin inclusion complex is formed withα-cyclodextrin; that is, 1-MCP/c/α-CD. A factor in addition to thosefactors mentioned above affecting 1-MCP release from 1-MCP/c/α-CD is theamount of water present in liquid or vapor form in the regionimmediately proximal to the treated substrate. This requiresconsideration of the amount of water released by respiring produce, andthe amount of water retained within the package as that amount changeswith plant respiration in the case of an enclosed or partially enclosedpackage that also includes the treated substrate.

In embodiments of the invention where 1-MCP/c/α-CD is employed in thecyclodextrin compositions and treated substrates of the invention, thetreated substrate is exposed to an atmosphere within the enclosedvolume, partially enclosed volume, or unenclosed volume that is proximalto one or more items of produce. This atmosphere must include anactivating amount of water such that the 1-MCP/c/α-CD releases the 1-MCPinto the vicinity of the produce at sufficient concentration to inhibitproduce ripening or maturation of the produce. Water sources includeambient humidity, water vapor and/or liquid water from the respirationof the produce itself, or water vapor or liquid water added in acontrolled amount in the vicinity of the cyclodextrin composition. Inembodiments, the cyclodextrin composition, the substrate or substrates,or both are permeable to both 1-MCP and to water vapor to a sufficientdegree to maintain a ripening or maturation inhibiting amount of 1-MCPin the vicinity of, that is, proximal to, the produce.

The water-facilitated release of 1-MCP from 1-MCP/c/α-CD is described indetail by Neoh, et al., Carbohydrate Research 345 (2010), 2085-2089. TheNeoh researchers studied dynamic complex dissociation of 1-MCP/c/α-CDand observed that increasing humidity generally triggered 1-MCP complexdissociation in a predictable manner. However, the dissociation wasgreatly retarded at 80% relative humidity, presumably owing to collapseof the crystalline structure; then abrupt dissociation corresponding tocomplex dissolution was observed at 90% relative humidity. However, theresearchers noted, as did present authors, that even at 100% relativehumidity that less than 20% of the complexed 1-MCP is released. In fact,an average of less than one-fifth (˜17.6%) of the total amount ofcomplexed 1-MCP was dissociated at the end of the experiments while˜83.4% 1-MCP remained complexed.

In some embodiments, during distribution and storage of packagedproduce, when storage temperature is between about 0° C. and 20° C., therelative humidity in an enclosed volume around the produce will bebetween about 50% and 100% due to normal water loss from producerespiration within an enclosed package volume. The increase in humiditywithin the enclosed volume of the package is sufficient, in embodiments,to release a portion of the 1-MCP from the 1-MCP/c/α-CD within anenclosed volume containing the cyclodextrin composition. In otherembodiments, the humidity surrounding a treated container is increasedby the addition of water in or around the container. In some suchembodiments humidity is increased around produce by adding moisture viawater mist, spray or steam during packaging, by controlling the humidityof the environment in the packaging location or within a storagefacility, or by adding water to a container immediately prior to formingan enclosed volume surrounding the produce.

The importance of the relationship between water and 1-MCP dissociationfrom a-MCP/c/α-CD is of utmost importance in employing the technologybecause:

-   -   1) the amount of 1-MCP is regulated in the atmosphere        surrounding fruits and vegetables on a country-by-country basis;        and    -   2) the benefit (i.e., shelf life extension) derived from 1-MCP        differs with exposure concentration for various types of produce        material (see, e.g. Blankenship, S. M. and Dole, J. M.,        Postharvest Biology and Technology 28 (2003), 1-25); further,        adverse effects to some produce materials are possible with        excessive 1-MCP treatment concentrations.        In two examples of country-by-country regulation, the United        States' Environmental Protection Agency (EPA) currently limits        1-MCP to a maximum of 1 ppm in air by authority of Section 408        of the Federal Food, Drug, and Cosmetic Act (FFDCA); and the        European Commission Health and Consumer Protection Directorate        and Member States of the European Food Safety Authority        similarly regulates 1-MCP under its various directives, limiting        1-MCP levels to amounts ranging from 2.5 ppb v/v to 1 ppm v/v.

Thus, in embodiments, 1-MCP dissociation must be carefully managedwithin a container headspace by controlling both the total amount of1-MCP incorporated within the container and the release of 1-MCP fromthe inclusion complex. Additionally, in embodiments, the amount ofresidual water inherently adsorbable or absorbable by the cyclodextrincompositions further affects 1-MCP dissociation. In embodiments, thehydrophilic nature of the cyclodextrin itself increases thecompatibility of water with the cyclodextrin composition into which acyclodextrin inclusion complex is incorporated.

In embodiments of the invention where the treated substrates employ1-MCP/c/α-CD as the cyclodextrin inclusion complex, the amount of 1-MCPin the atmosphere that is required for a particular application iscalculated based on several factors, as is discussed above; then thecoating thickness and area coated (that is, the total coating volume) isvaried based on the volume of the produce containing environment to beaddressed, the enclosed, partially enclosed, or unenclosed nature of theenvironment to be addressed, concentration of 1-MCP/c/α-CD included inthe cyclodextrin composition, and approximate fraction of 1-MCP/c/α-CDthat is complexed (vs. uncomplexed α-CD) to arrive at the targetedatmosphere. Factors that must be considered in such a calculationinclude any humectants or desiccants within the container, thesubstrate, or the cyclodextrin composition itself; water and 1-MCPpermeability/adsorbability/absorbability of the cyclodextrincomposition, water and 1-MCP permeability/adsorbability/absorbability ofthe substrate (or substrates, in the case of a treated laminate), anycontrolled or modified atmosphere present within the container, andrespiration rate of the targeted produce material.

For example, if an atmosphere containing 1 ppm of 1-MCP is required anda targeted enclosed volume is 1 liter, then assuming 100% 1-MCPcomplexation and an overall density of the cyclodextrin composition of 1g/cm³, a cyclodextrin composition containing 1.71 wt % α-cyclodextrincoated 12.7 μm thick in an area totaling 2 cm² would provide thetargeted 1 ppm of 1-MCP to the enclosed volume in the presence of watervapor using Ideal Gas Law conversion. In embodiments, the targetedweight range of 1-MCP/c/α-CD is 25 micrograms to 1 milligram per 1 literof enclosed volume. In such calculations, the value of delivering atargeted coating amount to the targeted enclosed volume is realized.Certain embodiments described above are particularly advantageous indelivering a precisely measured amount of 1-MCP to a selected volume, aswell as enabling an easily varied amount of cyclodextrin composition toa target container.

As described above, the use of flexographic printing is well understoodto deliver precise and easily varied volumes of material to substratesover an easily varied volume. We have demonstrated in the Examples belowthat this approach works well to deliver a precise and controlled amountof cyclodextrin composition to the targeted substrate, which in turnprovides a reproducible and low level of release in the presence ofwater vapor.

6. Certain Additional Embodiments

The following definitions apply in relation to sections 1-5 above. Thedefinitions in this section apply only to this section.

-   -   Device (for retarding plant spoilage) means “article” or        “treated laminate” as defined in section 1, as determined by        context.    -   Interior layer or exterior layer means the first or second        substrate of the treated laminate of section 1.    -   Encapsulating agent means “carrier” as defined in section 1.    -   Carrier or complexing agent are broad terms that are employed as        “cyclodextrin” is employed in section 1, that is, as a means to        complex the active ingredient.    -   Active ingredient or active means “olefinic inhibitor” as        defined in section 1.    -   Storage unit means “article” or “container” as defined in        section 1, as determined by context.

Disclosed herein is a device for retarding plant spoilage which includesan exterior layer and a water vapor permeable interior layer with anencapsulating agent positioned between the exterior layer and theinterior layer. The encapsulating agent encapsulates a carrier and anactive ingredient associated with the carrier. The purpose of the activeingredient is to retard plant spoilage due to the presence of ethylenegas inside sealed storage units commonly used for storage and transportof plant material such as, for example, fruits and vegetable. Theseactives are meant to be released into the headspace of such storageunits due to the water vapor that also resides within the headspace ofthe storage unit. The water vapor causes the active ingredient to bereleased from carrier with which it is associated thereby allowing theactive ingredient to inhibit the effects of the ethylene gas within theheadspace of the storage unit as ethylene is a known facilitator ofplant ripening and spoilage. Some actives used to prevent such spoilagecan be prematurely released due to exposure to, for example, the normalhumidity of the surrounding air in the area in which it is stored priorto use. The encapsulating agent serves to protect the active ingredientfrom premature exposure to water vapor it may encounter prior to use yetwithin the headspace of the storage unit, the encapsulating agent willstill permit the active ingredient and carrier to be contacted by thewater vapor so as to release the active ingredient within the headspaceto facilitate the retardation of the plant spoilage. To assist thecontact of the active by the water vapor, it is desirable that at leastthe interior layer be permeable to water vapor and so it is desirablethat the interior layer have a water vapor transmission rate greaterthan 3.0 g×mil/100 in²×day.

In some applications, it may be desirable that the exterior layerresists permeation of water vapor to the interior space of the device.In such instances, it is desirable that the exterior layer have a watervapor transmission rate less than 3.0 g×mil/100 in²×day.

To facilitate the functioning of the encapsulating agent, it isadvantageous that the encapsulating agent be non-aqueous. Otherdesirable properties of the encapsulating agent are; that it have amelting point less than about 80° C., that it be a semi-solid at roomtemperature, and that it have a glass transition temperature (Tg) ofabout minus 200° C. to about 20° C.

Suitable encapsulating agents include animal waxes, vegetable waxes,mineral waxes, synthetic waxes, bayberry wax, beeswax, stearyldimethicone, stearyl trimethicone, polyethylene, ethylene-alpha olefincopolymers, ethylene homopolymers, C₁₈-C₄₅ olefins and poly alphaolefins with ethylene-alpha olefin copolymers, ethylene homopolymers,C₁₈-C₄₅ olefins and poly alpha olefins being a preferred subset of thisgroup.

Due to the fact that some active ingredients are gases in their naturalstate and unstable, it is often desirable that the carrier be acomplexing agent capable of complexing with the active ingredient.Cyclodextrin is one carrier material that has been found to workparticularly well and alpha-cyclodextrin has been found to workparticularly well, especially when the active ingredient is 1-methylcyclopropene.

The device containing the encapsulating agent along with the carrier andactive ingredient is designed to be used inside a storage device forplant material. In some instances, it may be desirable for the exteriorlayer of the device to have an attachment means for attaching theexterior layer to another surface such as an inside surface of thestorage unit. To protect the attachment means, it can optionally becovered with a peelable release strip which can be removed from theattachment means prior to its attachment to another surface. Theinterior layer is permeable to water vapor. To further protect theactive ingredient within the interior space between the interior andexterior layers, the interior layer may be protected by a release linerwhich covers all or a portion of the exterior surface of the interiorlayer and which can be removed once the device is placed within theheadspace of a storage unit. Thus, it is desirable that the releaseliner have a higher degree of resistance to water vapor than theinterior layer. Alternatively stated, the release liner should have alower water vapor transmission rate than the interior layer.

To further protect and encapsulate the encapsulating agent, the carrierand the active ingredient, at least a portion of the exterior layer andthe interior layer of the device can be sealed to one another by aperipheral seal to prevent leakage of the encapsulating agent and thecarrier from the device.

The storage unit in which the device is placed can comprise a sealedpackage layer which defines an interior space, which is also referred toas the headspace. The device can simply be placed inside the storageunit in such a manner that it is free to move about within the headspaceor, as previously mentioned, it may be attached to an interior surfaceof the sealed package layer forming all or a portion of the storageunit.

To further integrate the device with the storage unit, in one embodimentthe storage unit can comprise a sealed package layer which defines aninterior space for storing plant material and the device can form atleast a portion of the sealed package layer.

In any of the foregoing storage unit designs, it may be desirable forthe unit to have means for opening and closing the storage unit.

Definitions Applying to this Section Only

The term “film” refers to a thermoplastic film made using a filmextrusion process, such as a cast film or blown film extrusion process.The film can be a monolayer, or a multilayer film or a laminate.

The term “water vapor permeable films” includes films, such asthermoplastic polymer-containing films, which permit the flow of waterthrough open or inter-connected pores. The term includes films renderedporous by puncturing or aperturing, and films rendered porous by mixingpolymer with filler, forming a film from the mixture, and stretching thefilm sufficiently to form liquid passages through the film.

The term “open-celled foam material” refers to a layer material madewith the aid of a foaming process, in which the cells in the foam createopen pores from one surface of the layer to the opposite surface. Theterm does not include foams which substantially block the flow of liquidwater, such as closed-cell foam materials unless they have beenapertured or otherwise modified to permit the transmission of waterand/or water vapor from one surface of the foam to another surface ofthe foam.

The term “polymer” includes, but is not limited to, homopolymers,copolymers, such as for example, block, graft, random and alternatingcopolymers, terpolymers, etc., and blends and modifications thereof.Furthermore, unless otherwise specifically limited, the term “polymer”shall include all possible geometrical configurations of the material.These configurations include, but are not limited to isotactic,syndiotactic and atactic symmetries.

The term “water vapor permeable” refers to a material present in one ormore layers, such as a film, nonwoven fabric, or open-celled foam, whichis porous, and which is water-permeable due to the flow of water inliquid or vapor form through the pores of the layer. The pores in thefilm or foam, or spaces between fibers or filaments in a nonwoven web,are large enough and frequent enough to permit leakage and flow ofliquid and/or vaporous water through the layer. The term does notinclude films and other materials which block the transfer of water orwater vapor.

The term “cyclodextrin compound” includes any compound which includesthe cyclodextrin ring structure, including derivatives of cyclodextrinsthat maintain the ring structure. The ring structure may be that of anα-cyclodextrin compound (6 glucose units), a β-cyclodextrin compound (7glucose units), a γ-cyclodextrin compound (8 glucose units), or acombination including compounds having one or more of these ringstructures.

Product Forms and Applications

One embodiment of a device 10 for retarding plant spoilage is shown inFIGS. 1 and 1A of the drawings. Turning to FIG. 1, the device 10includes an exterior layer 12, a water vapor permeable interior layer14, an encapsulating agent 16, a carrier material 18 and an activeingredient 20. As will be explained in greater detail below, in manyembodiments, it will be desirable that the exterior layer be water vaporimpermeable. The active ingredient 20 is associated with the carriermaterial 18 and this combination is encapsulated within and coated bythe encapsulating agent 16 and the combination of the encapsulatingagent 16, the carrier material 18 and the active ingredient 20 arepositioned between and contained by the exterior layer 12 and theinterior layer 14. To contain these materials (16, 18 and 20), at leasta portion of the exterior layer 12 and the interior layer 14 may besealed to one another such as by a peripheral seal 22. In addition,optionally, an attachment means 24 such as a layer of adhesive or otherbonding material may be applied to an exterior surface of the device 10such as the exterior layer 12 or the interior layer 14 so that thedevice can be adhered to another surface such as the inside of a storageunit 30 as shown in FIGS. 2 and 3.

As explained in further detail below, in one embodiment, theencapsulating agent 16 is polyolefin wax (also referred to aspetrolatum), the carrier material 18 is cyclodextrin and the activeingredient is 1-MCP which has been complexed with cyclodextrin.

In operation, the encapsulating agent 16, which is hydrophobic innature, surrounds and coats the carrier 18 and active 20 thus protectingthem from premature exposure to water and/or water vapor. However, asthe device 10 is handled, water and/or water vapor can penetrate throughthe water vapor permeable interior layer 14 and come in contact with thecarrier/active inside the device 10. Since cyclodextrin is hydrophilic,moisture condenses on it and through capillary action, moisturedisplaces 1-MCP from the cyclodextrin cavity. A detailed description ofthe mechanism and kinetics of the release of 1-MCP from cyclodextrin bycontact with moisture can be found in the article entitled “Dissociationcharacteristic of the inclusion complex of cyclomaltohexaose(a-cyclodextrin) with 1-methylcyclopropane in response to stepwiserising relative humidity”, by Tze Leon Neoh, et al., CarbohydrateResearch, 345 (2010), 2085-2089 which is incorporated herein byreference it its entirety.

As the plant package is handled, the device 10 inside the package willtwist and flex by its own movement inside the package as well as by thecontacting of the device 10 by the plant material inside the package,thereby exposing more of the encapsulated carrier/active to thewater/water vapor inside the package and therefore releasing more of theactive ingredient 20 into the headspace of the package.

Turning to FIGS. 2 and 3 there is shown a storage unit or package 30which in this case is a plastic food storage bag such as is commonlyused to store and sell individually-sized packages of perishable producesuch a fruits and vegetables in grocery stores. The storage unit 30includes a sealed package layer 32 which defines an interior space 34and houses a perishable plant material 36. The airspace surrounding theplant material 36 is referred to in the industry as the headspace whichis also referenced by element 34 and the two words are meant to be usedinterchangeably. It is this headspace 34 which contains the gasesemitted by the plant material 36 including ethylene. The headspace 34also contains oxygen and carbon dioxide.

As shown in FIGS. 2 and 3, the device 10 is located within the headspace34 of the storage unit 30. The device 10 may simply be placed inside theheadspace 34 along with the plant material 36 or it may be affixed tothe interior surface of the storage unit 30 as by way of an attachmentmeans 24 such as, for example, an optional adhesive layer 24 located on,for example, an exterior surface of the device 10 such as the exteriorlayer 12 shown in FIG. 1A. Alternatively, the attachment means 24 may beapplied to an interior surface of the storage unit 30 and the exteriorlayer 12 of the device 10 may be adhered to the attachment means 24.Still further, if desired, the device 10 may be attached to the storageunit 30 by any other suitable attachment means such as by heat sealingor taping it to the storage unit 30.

Turning to FIGS. 4 and 5, there is shown another storage unit 40. Inthis embodiment, all or a portion of the sealed package layer 42 may beformed of the device 10. As shown in FIGS. 4 and 5, one side 43 of thestorage unit 40 is formed of the device 10 with the exterior layer 12forming the exterior surface of the storage unit 40.

While the storage units 30 and 40 shown in FIGS. 2 through 5 are in theform of small individual packages for end-consumer use, it should beappreciated that the present invention can be scaled up or down to fitany suitable storage unit. Plant material such as fruit, vegetables andornamentals such as flowers are subject to degradation from the point ofinitial harvesting until the end of the use cycle by the end-user. As aresult, such items may be placed in and transferred to multiple storagesunits as part of this cycle. Thus, the present invention is intended tobe used in any of such storage units.

Referring to FIG. 6, individual devices 10 may be made in roll form 50with perforations or other separation means 52 between the individualdevices 10 so they can be separated from one another and be placed intoindividual storage units 30 (note shown). Alternatively, theperforations or other separation means 52 may be omitted and a cuttingmechanism (not shown) may be used to cut and separate the individualdevices 10 of the roll 50 by cutting through the peripheral seal 22between individual devices 10.

In the consumer area, smaller versions of these rolls 50 or stacks ofindividual, separate or folded devices 10 may be sold in packages forthe consumer to use in conjunction with both disposable and re-useablefood storage cartons such as sealable plastic bags and plasticcontainers with sealable lids. In such applications, whether in rollform or in individual stacks, the devices 10 may be provided with theaforementioned attachment means 24 located on the exterior surface ofthe exterior layer 12. See FIG. 7. As a result, it may be desirable toprotect the attachment means 24, which in this example is an adhesivepatch 24, with a peelable release strip 25 as shown in cross-section inFIG. 7. Such peelable release strips 25 are well known and commonlyemploy a paper or other substrate, at least one side of which typicallyhas been coated with a release coating such as a layer of silicone whichcontacts the adhesive 24. Further, to protect the water vapor permeableinterior layer 14, the exterior surface of the interior layer 14 mayalso be protected by a release liner 26 which can be peeled off theexterior surface of the interior layer 14 prior to use. See FIG. 7. Therelease liner 26 will typically have a layer of adhesive 27 or othersuitable attachment means affixed thereto.

In yet a further embodiment, the individual devices 10 may be wrappedand sealed in individual pouches 60, such as is shown in cross-sectionin FIG. 8, much like other products such as, for example, individuallywrapped sanitizing wipes. In so doing, the devices 10 can be keptairtight and protected from premature exposure to water and water vaporprior to use. In this application, if an attachment means such as anadhesive layer 24 is used, it may once again be protected by a releasestrip 25 (not shown) or the interior surface of the pouch may act as therelease strip 25.

In yet another embodiment (not shown), the present invention may bescaled to use in very large containers where large volumes of plantmaterial are stored and transported such as in sea containers. In suchapplications, the container wall itself may serve as the exterior layer12, the combination of encapsulating agent 16, carrier material 18 andactive ingredient 20 may be applied to the interior wall in bulk formsuch as by brushing or spraying and then covered with an interior layer14 which may be adhesively or otherwise attached or removably attachedto the wall of the container which serves as the exterior layer 12.Alternatively, the encapsulating agent 16, carrier material 18 andactive ingredient 20 may be impregnated into or coated onto anothersubstrate such as a foam material or a fibrous nonwoven web such as aspunbond web or a staple fiber web which can in turn be secured betweenthe exterior layer 12 and the interior layer 14.

Next a more detailed explanation of the various components of the device10 will be undertaken.

Exterior Layer

The exterior layer 12 should resist transmission of water and/or watervapor into the interior portion of the device 10 between the exteriorlayer 12 and the interior layer 14 where the carrier material 18 and theactive ingredient 20 are located. In applications where plastic filmsand bags are being used, it is desirable that the exterior layer 12 bemade from polymers that employ desirable properties. Examples of suchproperties include that the material be flexible, transparent forviewing the condition of the package contents, haze-resistant,printable, sealable, puncture resistant and impermeable to water andwater vapor and, optionally, the passage of gases such as oxygen, carbondioxide and ethylene.

Any number of film-forming polymers may be used to form the exteriorlayer 12. Examples of film-forming polymers include, but are not limitedto, polyolefins, polyolefin plastomer polymers (POP), ultra-low densitypolyethylene (ULDPE), linear low density polyethylene (LLDPE), lowdensity polyethylene (LDPE), styrene-butadiene copolymers, ethylenevinyl acetate (EVA) and very low density polyethylene (VLDPE). It isdesirable in some applications that the exterior layer 12 be impermeableto water and water vapor/moisture so that the active 20 is notprematurely released. This is particularly true when the exterior layer12 forms all or a portion of the food storage unit 30 such as a plasticfood storage bag or container. However, if the device 10 is to be usedinside storage unit 30, it may be desirable to have the exterior layer12 be permeable to water and water vapor/moisture. A measure of whethera film or other material is water vapor permeable or impermeable is bymeasuring its water vapor transmission rate or WVTR. This value can bedetermined in accordance with ASTM test method F1249-06 (Reapproved2011) (at 38° C. and 100 percent relative humidity) which isincorporated herein by reference in its entirety. When it is desiredthat this layer 12 be water vapor impermeable, the layer 12 should havea WVTR less than 3.0 g×mil/100 in²×day (1.18 g×mm/m²×day) and desirablya WVTR of between about 0.5 g×mil/100 in²×day (0.20 g×mm/m²×day) andabout 2.0 g×mil/100 in²×day (0.79 g×mm/m²×day). Note that multiplyingthe units of g×mil/100 in²×day by 3.937008×10⁻¹ will convert the unitsto g×mm/m²×day.

The film used to form the exterior layer 12 may be a single layer filmor it may be a multilayer film or a laminate of one or more layers. Inaddition, if desired additional layers may be adhered or otherwisejoined to the film including, but not limited to, fibrous nonwoven websand other materials. If it is desired that the exterior layer 12 bepermeable below with respect to the interior layer 14.

A number of suitable polymers are available from the Dow ChemicalCompany of Midland, Mich. including, but not limited to, Dow® AFFINITY™polyolefin plastomers such as Dow® AFFINITY™ PF 1140G POP and ultra-lowdensity polyethylene films such as Dow® ATANE™ ULDPE.

Interior Layer

The interior layer can be made from a wide variety of film-formingpolymers provided the resultant layer is permeable to water and/or watervapor. Such breathable films are well known in the art. Examples ofsuitable polymers include, but are not limited to, polyolefins,polyolefin plastomer polymers (POP), ultra-low density polyethylene(ULDPE), linear low density polyethylene (LLDPE), low densitypolyethylene (LDPE), styrene-butadiene copolymers, ethylene vinylacetate (EVA) and very low density polyethylene (VLDPE). Filled andstretched films are also suitable films for the interior layer 14. Suchfilms are widely known in the art. They are typically made by mixing acertain quantity of a filler, such as calcium carbonate, into the filmpolymer, forming the filled polymer into a film and then stretching thefilm to make it breathable and able to pass water and water vapor. Inaddition, apertured films are also suitable for the interior layer 14and such films are also widely known in art.

A number of suitable film polymers are available from the Dow ChemicalCompany of Midland, Mich. including, but not limited to, Dow® AFFINITY™polyolefin plastomers such as Dow® AFFINITY™ PF 1140G POP and ultra-lowdensity polyethylene films such as Dow® ATANE™ ULDPE.

In addition to films, foam materials (such as open-cell foams) may alsobe used as may fibrous nonwoven webs (such as spunbond webs, meltblownwebs, staple fiber webs and combinations of the foregoing) as well aslaminates of any or all of the aforementioned films, foams and fibrousnonwoven webs.

Films used to form the interior layer 14 should have a water vapor rategreater than 3.0 g×mil/100 in²×day (1.18 g×mm/m²×day) and desirablybetween about 3.5 g×mil/100 in²×day (1.38 g×mm/m²×day) and about 6.0g×mil/100 in²×day (2.36 g×mm/m²×day) in accordance with theaforementioned ASTM test F1249-06 (Reapproved 2011) (at 38° C. and 100percent relative humidity).

Encapsulating Agent

The purpose of the encapsulating agent 16 is to protect the combinationof the carrier material 18 and the active ingredient 20 from prematureexposure to water and/or water vapor and replacement of the activeingredient 20 complexed with the carrier material 18 by the water and/orwater vapor and to laminate exterior layer 12 and the interior layer 14together. The time between the original complexing of the active 20 withthe carrier 18 and the actual use of the combination within theheadspace 34 of the storage unit 30 may be quite long. If thiscombination is not adequately protected, it can prematurely interactwith environmentally present moisture/humidity and begin to lose itseffectiveness prior to such time as the carrier/active combination hasbeen loaded into the headspace 34 of a storage unit 30 where it isintended to work.

While it is desirable that the water contained inside the storage unit30 operate to release the active 20 into the headspace 34 of the storageunit 30 to retard ripening and/or spoilage of the plant material 36contained in the storage unit 30, this replacement process should nottake place prematurely, that is, before the perishable contents 36 andthe device 10 are contained in the headspace 34 of the same storage unit30.

To adequately protect the active ingredient 20, it is desirable that theencapsulating agent 16 have a number of properties including, but notlimited to, being non-aqueous, having a low crystallinity and beingamorphous. The encapsulating agent 16 must be non-aqueous due to thereactive nature of the active ingredient 20 with water and water vapor.By being amorphous and having a low crystallinity, the encapsulatingagent 16 is sufficiently closed to protect the active from water andmoisture but also sufficiently open and porous so the structure of theencapsulating agent 16 will permit access to the active ingredient,especially when the device 10 is handled and transported as well as whenthe device 10 is manipulated by contact with the plant material 36contained within the headspace 34. Suitable encapsulating agents aredesirably semi-solid at room temperature and should have a melting pointless than about 80° C. and desirably less than about 50° C. Mosttypically, the melting point of the encapsulating agent 16 will rangebetween of about 40° C. and about 80° C.

It is also desirable that the encapsulating agent 16 have a glasstransition temperature (Tg) of between about minus 200° C. and about 20°C. and more desirably between about minus 30° C. and about 20° C.

Suitable encapsulating agents may include, for example, waxes includinganimal waxes, vegetable waxes, mineral waxes and synthetic waxes.Exemplary waxes include, but are not limited to, bayberry wax andbeeswax. Other suitable materials include petrolatum, stearyldimethicone, stearyl trimethicone, polyethylene, ethylene-alpha olefincopolymers, ethylene homopolymers, C18-C45 olefins and poly alphaolefins. Commercially available ethylene homopolymers include Petrolite™EP copolymers from Baker Hughes Inc. of Sugar Land Tex. and poly alphaolefins such as Vybar™ polymers also from Baker Hughes Inc.

Carrier Material

The carrier material 18 should be hydrophobic and water insoluble and,if necessary, be able to complex with the active ingredient. Forcomplexing to occur, a carrier (or host), is used to stabilize aninherent unstable or volatile active (or guest) by forming a stable“carrier/active” inclusion complex (or guest-host complex). Theinclusion complex allows the active to remain stable at ambientconditions until a specific stimulus is provided that will trigger therelease of the active from the carrier. In the specific instance, thestimulus which allows the active to be released from the complex iswater vapor. In one embodiment of the present invention, the host can becyclodextrin and the guest is the 1-MCP.

One measure of whether a material is hydrophobic is its contact anglewhich should be at least 90°. One suitable instrument for measuringcontact angles is a Rame-Hart model number 200 Contact Angle Goniometerequipped with a Leica APO lens and a Sony 3CCD exwave HAD camera whichis available from the Rame-Hart Instrument Company of Mountain Lakes,N.J. The contact angle can be measured by producing a drop of liquid ona solid. The angle formed between the solid/liquid interface and theliquid/vapor interface is referred to as the contact angle. The mostcommon method for measurement involves looking at the profile of thedrop and measuring two-dimensionally the angle formed between the solidand the drop profile with the vertex at the three-phase line. It is alsodesirable for the carrier to be water insoluble. For purposes of thepresent invention, the water insolubility should be less than or equalto 0.2 grams per 100 milliliters of water at 20° C.

One particularly well-suited carrier material 18 is a cyclodextrin (alsoreferred to herein as “CD”) which has been found to complex very wellwith the active ingredients 20 including 1-MCP. Suitable cyclodextrincompounds include compounds derived from cyclodextrins containing fromsix to twelve glucose units, including without limitationalpha-cyclodextrins (6 glucose units arranged in a ring),beta-cyclodextrins (7 glucose units arranged in a ring), andgamma-cyclodextrins (8 glucose units arranged in a ring). It has beenfound, however, that alpha cyclodextrin is the preferred carriermaterial with respect to the petrolatum encapsulating agent due to thesize exclusion effect which precludes the beta and higherglucose-containing units from readily accepting the petrolatum andallowing the encapsulating agent to migrate inside the cyclodextrin. Thecoupling and configuration of the glucose units causes the cyclodextrinsto have a conical molecular structure with a hollow interior lined byhydrogen atoms and glycosidic bridging oxygen atoms.

The cyclodextrin compound should be capable of complexing with theactive ingredient 20 and being coated with the encapsulating agent 16 toprevent premature exposure to water and/or water vapor which couldprematurely release of the active ingredient 20 from the carriermaterial 18. Suitable cyclodextrin compounds includemethacryloyl-R-cyclodextrins, where R is an alkyl group having 2-20carbon atoms, desirably 4 to 10 carbon atoms; acryloyl-R-cyclodextrins,where R is an alkyl group having 1 to 20 carbon atoms, desirably 4 to 10carbon atoms; alkenyl succinylated cyclodextrins, where the alkenylgroup has 2 to 20 carbon atoms, desirably 4 to 10 carbon atoms; and thelike. The cyclodextrin compound may have a degree of substitutionranging from about 0.1 to about 7. Particularly suitable cyclodextrincompounds include methacryloyl-beta-cyclodextrins, which is acyclodextrin derivative having an attached methacryloyl moiety that ispolymerizable. Polymerization of the methacryloyl-beta-cyclodextrin canbe achieved via a radical propagation mechanism and using commonchemical or radiation initiation techniques. One presently preferredcyclodextrin compound is 2-hydroxy-3-methylacryloyloxy-propyl-betacyclodextrin.

Active Ingredient

The purpose of the active ingredient is to help retard plant spoilageand, in particular, plant spoilage associated with exposure of the plantmaterial to ethylene gas. Most typically during plant material transportand storage, the source of the ethylene gas is the plant material,itself. Many chemical compounds have been identified as useful in theretardation of plant material spoilage. There are several different wayssuch chemicals work. Some chemical compounds are referred to as“ethylene inhibitors” while others are referred to as “ethylenescavengers”. For a more detailed explanation of how ethylene inhibitorswork see Schotsmans, W. C.; Prange, R. K.; Binder, B. M. InHorticultural Reviews; Janick, J., Ed.; John Wiley and Sons: New Jersey,2009; Vol. 35, pp 263-313 which is incorporated herein by reference inits entirety and the previously mentioned Tze et al. article. Also see“Ethylene: The Ripening Hormone” by Sylvia Blankenship published by theWashing State University Tree Fruit Research and Extension Center, Nov.12, 2012 (http://postharvest.tfrec.wsu.edu/pages/PC2000F) which isincorporated herein by reference in its entirety.

Examples of such inhibitors include, but are not limited to, carbondioxide, silver thiosulfate, cyclopropene, cyclooctene, cyclooctadieneand 1-methyl cyclopropene. In one of the embodiments of the presentinvention the active ingredient 20 is 1-MCP. When the water and/or watervapor contained in the headspace 34 of the storage unit 30 comes incontact with the carrier material 18, the water/water vapor replaces thecomplexed active ingredient 20, which is this embodiment is 1-MCP, fromthe carrier material 18 (which in this case is cyclodextrin) and the1-MCP is released into the headspace 34 of the storage unit 30. The1-MCP contacts the plant material 36 and binds with the ethylene plantreceptors in the plant material. See, for example, US Patent ApplicationNo. 2006/0154822 to Toivonen et al. which is incorporated herein byreference in its entirety and the aforementioned article by Tze et al.

Experimental Section

Analytical Test Method

Samples were placed into a clean 250 mL serum bottle with TEFLON® facedsilicone septa at time zero (t₀). The serum bottle was maintained atroom temperature (about 20° C.) during the indicated test interval. Atthe indicated sampling interval, the serum bottle headspace was sampledby removing 1 mL of gas from the sample bottle. The 1-butene headspaceconcentration surrounding the test film was quantified using gaschromatography of the 1 mL gas sample.

A gas chromatograph (HP 5890, obtained from the Hewlett Packard Companyof Palo Alto, Calif.) operated with flame ionization detection (FID), asix-port heated sampling valve with 250 μL sampling loop and datacollection software (HP ChemStation A06.03-509) was used to measure the1-butene headspace concentration. Static headspace concentration wasdetermined in test samples using a five point 1-butene calibration curvemeasured in μL of 1-butene per 250 mL bottle volume and presented asμL/L, or parts per million (vol/vol). Sampling of the serum bottles wasaccomplished directly through a Valco Instrument six port manual gassampling valve (Valco #DC6WE, obtained from Valco Instruments Company,Inc. of Houston, Tex.) with 250 μL sampling loop interface directly to aRTx-5 GC column, 30 m×0.25 mm I.D., 0.25 film (obtained from Restek,Inc., of Bellefonte, Pa.). The GC operating conditions are shown inTable 1.

TABLE 1 HP 5890GC Operating Conditions Set Point Zone Temperatures: Sixport valve 120° C. Detector (FID) 150° C. Oven zone: 30° C.Equilibration Time 0.0 min. Oven Program: Isothermal Temp: 150° C.Initial Time (min): 1.20 Run Time (min): 1.20The 1-butene working standard was prepared by diluting 10 mL of 99.0%pure 1-butene gas (Scotty Gas #BUTENEO1, obtained from the Sigma AldrichCorporation of St. Louis, Mo.) in a TEDLAR® gas sampling bag containing1 liter of air. The 1-butene working standard concentration was 10,226μL/L (PPM).

Calibration standards were prepared at five concentration levels byinjecting via a 250 μL gas tight syringe (Hamilton Gastight® #1725) 50,100, 200, 300 and 400 μL of the working standard into 250 mL the serumbottles fitted with Teflon® faced silicone septa. ChemStation softwarewas used to calculate a 1-butene response factor using a linearregression equation. The 1-butene standard curve correlation coefficientwas 0.999.

EXAMPLE 1

An inclusion complex of 1-butene and α-cyclodextrin was formed using thetechnique described by Neoh, T. L. et al., J. Agric. Food Chem. 2007,55, 11020-11026 for forming 1-MCP/c/1-MCP, except that 1-butene (99.0%pure, obtained from Scott Specialty Gases of Plumsteadville, Pa.) wasbubbled through a saturated α-cyclodextrin solution instead of 1-MCP. Aprecipitate formed which was collected by filtering through a 10 micronfitted filter and dried at ambient temperature at 0.1 mm Hg for about 24hours. The precipitate was termed “1-butene/c/a-CD.”

The 1-butene/c/a-CD was analyzed by adding 100 mg of the collected anddried precipitate to a 250 mL glass bottle equipped with a septum cap,taking care to ensure that no powder adhered to the walls of the bottle.After about 1 hour, 1 mL of headspace gas was sampled by GC using the GCtechnique described above. No measurable concentration of 1-butene wasdetected. Then 3 mL of water was injected into the bottle through theseptum, and the bottle was placed on a mechanical shaker and mixedvigorously for about 1 hour. Then 250 μL of the headspace gas wasremoved and added to an empty 250 mL bottle equipped with a septum cap,wherein the interior of the bottle was purged with nitrogen gas.

The headspace concentration of 1-butene was quantified in the secondbottle using gas chromatography by removing 250 μL of gas from the 250mL bottle using the GC method described above, further wherein the FIDdetector was previously calibrated, using the 1-butene calibrationstandards described above, with a 6-point 1-butene calibration curve.Employing this method, the yield of complexed 1-butene/c/a-CD was foundto be 94.5%.

EXAMPLE 2

A cyclodextrin composition was applied to a continuously moving flexibleweb using flexographic printing methodology. A petrolatum compositionwas formed by immersing a container having a known weight of petrolatum(VASELINE®, melting point 38°-56° C., obtained from Sigma AldrichCorporation of St. Louis, Mo.) in a water bath at 70° C. untilliquified, and mechanically dispersing 4 wt % 1-butene/c/α-CD into theliquefied petrolatum using low shear mixing. The mixture is referred toas Composition 1.

Flexographic printing was carried out using a narrow web rotary printingpress (340 mm wide flexographic press obtained from Gallus Inc. ofPhiladelphia, Pa.). Flexible plates made of engineered photopolymer andhaving a raised discontinuous diamond relief pattern covering 40% of theplate surface area were adhered to the plate cylinder. The filmsubstrate used for printing was a high barrier film (EXXON MOBIL® BICOR®210 ASB-X, acrylic and PVdC coated oriented polypropylene, 33 cm wide,obtained from the EXXON MOBIL® Corporation of Irving, Tex.). Thefountain trough was loaded with Composition 1. Hot air was blown overthe fountain roll to keep Composition 1 liquified. The liquifiedComposition 1 was applied to the photopolymer plate using a 300 linesper inch (118 lines/cm, 8.35 bcm) anilox roll. The printing press wasrun at 100 to 150 ft/min (30.5 to 45.7 m/min). The printed Composition 1was then ‘hard-set’ using a chill roll is filled with dry ice pellets.Then the entire web surface was coated inline with a UV laminationadhesive (RAAL00160/1060DHV UV/EB Curable Adhesive, obtained from ACTEGAWIT, Inc. of Lincolnton, N.C.) coated via flexo printing, using a 500lines/in (197 lines/cm, 5.02 bcm) anilox roll before joining a secondsubstrate to the adhesive. The second substrate was a 1 mil (25.4 μm)thick, low density polyethylene (LDPE) web (MI=1.8 g/10 min, density0.921 g/ml, Vicat sotening point 100° C.) which was applied at a nip,and radiation curing of the adhesive was carried out using UV lampsmounted immediately after the nip point to prevent separation or airpockets in the laminated film. Curing was accomplished with a 300watt/inch lamp. The completed Treated Laminate 1, a treated laminatecontaining Composition 1 printed in a diamond pattern, was wound up.

In this manner, Composition 1 was disposed between the two substratelayers of Treated Laminate 1, wherein directsubstrate-adhesive-substrate contact in the interstitial areas providedby the diamond pattern effectively isolated Composition 1 into“islands”. The isolated islands of the cyclodextrin composition providefor ease of windup, storage, and use. Further, when placed in acontainer having an item of produce also contained therein, Composition1 will not contact the produce directly. No petrolatum can contact withthe packaged food, and no petrolatum migration is possible.

EXAMPLE 3

Three 10 cm×30.5 cm rectangular samples were cut from TreatedLaminate 1. Each sample was loosely rolled up and placed into a separateclean 250 mL bottle for testing according to the Analytical Test Methodoutlined above. Each bottle was injected with 50 μL of deionized waterat t₀. Care was taken so that the liquid water did not directly contactthe film. Bottle headspace was analyzed for 1-butene at four timeperiods: 2, 22, 44, and 72 hours after the injection of water, using theGC technique of Example 1. The average headspace concentration of1-butene and standard deviation for each of the three samples aretabulated in Table 2. The results show that greater amounts of 1-butenewere released into the headspace from the laminated film substrate withincreasing time.

TABLE 2 Amount of 1-butene released as a function of time. 2 hr 22 hr 44hr 72 hr 1-Butene 1-Butene 1-Butene 1-Butene Sample ppm ppm ppm ppm A0.54 17.3 20.2 19.9 B 0.49 16.3 18.2 17.9 C 0.53 14.9 18.0 18.1 Ave.0.52 16.2 18.8 18.6 Stdev 0.03 1.2 1.2 1.1

EXAMPLE 4

The α-cyclodextrin was complexed with from 1.0 to 2.25 weight percent1-butene based upon the weight of the combined 1-butene andα-cyclodextrin. A mixture of 10 weight percent α-cyclodextrin and 90weight percent petrolatum were mixed in a beaker. The beaker was thenplaced on a hot plate at 50° C. for about 30 minutes and stirred untilthe petrolatum melted. A clear and homogeneous dispersion was obtained.The dispersion was then applied to a polyethylene film to an add-on ofabout 50 weight percent, based upon the weight of the film, via a Meyerrod (#20) to produce a thin coating. Finally a second polyethylene filmwas placed on top of the coating in such a way that thealpha-cyclodextrin/1-butene/petrolatum coating was sandwiched betweenand laminated the two polyethylene films.

Two samples as described above were prepared and then tested todetermine the level of release of the 1-butene from the device. Two inchby eight inch (5.1×20.3 centimeter) samples of the material were cut andplaced in separate 250 milliliter (mL) bottles each of which washumidified with 100 microliters of water and each bottle was sealed witha silicone septa seal. The bottles were maintained at a temperature of20° C. throughout the testing cycle. Samplings of the environment withineach bottle were done at zero hours and subsequently at one, two, fourand sixteen hours. The samples were subjected to gas chromatography tomeasure the level of 1-butene released into the closed environment ofthe bottles. The amounts of measured 1-butene in parts per million (PPM)for the two samples (Sample A and Sample B) are set forth below in Table3.

TABLE 3 Amount of 1-butene released as a function of time. Sample Hour1-Butene (ppm) A 0 0.22 A 1 54.76 A 2 110.63 A 4 179.73 A 16 415.80 B 00.44 B 1 35.26 B 2 67.89 B 4 114.60 B 16 307.26

As can be seen from the data, despite being encapsulated in petrolatum,the moisture vapor within the sealed environment was able to access the1-butene complexed with the alpha-cyclodextrin and cause the 1-butene tobe released into the closed environment thereby simulating the headspaceof a sealed package as would contain plant material such as fruits andvegetables to thereby retard the ripening and degradation of the storedplant material.

This method can easily be practiced commercially on a film foodpackaging line where an α-cyclodextrin/1-MCP complex is formulated inpetrolatum and applied via slot die while sandwiched between two filmlayers, one of both of which are breathable. The film layers can havedifferent thicknesses and water vapor transmission rates to allow formoisture access to the alpha-cyclodextrin/1-MCP complex which cansubsequently trigger the release of 1-MCP in the headspace of thestorage unit containing fresh cut fruits and vegetables.

The invention illustratively disclosed herein can be suitably practicedin the absence of any element which is not specifically disclosedherein. While the invention is susceptible to various modifications andalternative forms, specifics thereof have been shown by way of examples,and are described in detail. It should be understood, however, that theinvention is not limited to the particular embodiments described. On thecontrary, the intention is to cover modifications, equivalents, andalternatives falling within the spirit and scope of the invention. Invarious embodiments, the invention suitably comprises, consistsessentially of, or consists of the elements described herein and claimedaccording to the claims.

What is claimed is:
 1. A treated laminate comprising a first substrate,a cyclodextrin composition coated on at least a portion of a surface ofthe first substrate, and a second substrate disposed over the coatedcyclodextrin composition in contact with the cyclodextrin composition,the cyclodextrin composition comprising: a cyclodextrin inclusioncomplex comprising a cyclodextrin compound and an olefinic inhibitor;and a carrier comprising petrolatum or a petrolatum-like material andhaving a melting transition onset between about 23° C. and 40° C. andsolubility in water of less than 1 wt % at 25° C., wherein the firstsubstrate is different from the second substrate, and the secondsubstrate is solidified after contacting the cyclodextrin composition.2. The treated laminate of claim 1 wherein the cyclodextrin compositionis coated on the first substrate in pattern.
 3. The treated laminate ofclaim 2 wherein the pattern is a continuous pattern.
 4. The treatedlaminate of claim 2 wherein the pattern is a discontinuous pattern. 5.The treated laminate of claim 2 wherein the pattern comprises 50% orless of the first substrate surface area.
 6. The treated laminate ofclaim 1 wherein the cyclodextrin inclusion complex consists essentiallyof α-cyclodextrin and 1-methylcyclopropene.
 7. The treated laminate ofclaim 1 wherein the carrier consists essentially of petrolatum.
 8. Amethod of making the treated laminate of claim 1, the method comprisingheating the cyclodextrin composition to a temperature between 60° C. and80° C., coating the heated cyclodextrin composition on a firstsubstrate, disposing a second substrate over the coated cyclodextrincomposition, and solidifying the second substrate.
 9. The method ofclaim 8 further comprising cooling the cyclodextrin composition afterthe coating and before disposing the second substrate.
 10. The method ofclaim 8 wherein the coating is pattern coating.
 11. The method of claim8 wherein the coating is die coating, slot coating, curtain coating,flood coating, gap coating, notch bar coating, wrapped wire drawdowncoating, dip coating, spray coating, rotogravure coating, or printcoating.
 12. The method of claim 11 wherein the print coating is aflexographic printing, inkjet printing, lithographic printing, lettersetprinting, or screen printing.